Does fixing driveline slack, fix jerky throttle?

[Beery]

I know driveline backlash has been death on here, but I'm becoming more and more of the opinion that it might be the cause of the horrible low speed driveability in Puma's.

Getting on the throttle after coasting is painful, no matter how gentle I am. Its just impossible to get a smooth transition from coasting to motoring.

It feels as though the driveline is constantly overrunning and underrunning the engine. And when you reapply throttle it takes up the slack, resulting in the annoying shunt.

It really does make you look like a hopeless driver at low speed.

The BAS Autobiography remap has reduced the problem, but it is still there.

[JDNSW]

The most common reason for this problem is a dragging handbrake - and it does not have to be dragging much. But transmission slack makes it worse.

John

[Beery]

Thanks John.
It rolls on the slightest gradient, so I don't think its dragging. It would've worn the brake shoes back by now anyway if it had been dragging.

[PAT303]

The most common reason for this problem is a dragging handbrake - and it does not have to be dragging much. But transmission slack makes it worse.

John

I've seen that many times,I've even seen a T/C replacement from the ''flapping'' sound they make on coast when the shoe's rub,the owner and mechanic refused to even back the hand brake off to prove my theory,anyway a wasted few grand. Pat

[Brett1066]

How does one go about checking if the handbrake is dragging and rectifying it if it is the cause?

[JDNSW]

Drive a few blocks and then put your hand on the drum - if it blisters, the brake is dragging. Should be slightly cooler than the transfer case.

Dragging can be due to adjustment - easy enough to slacken it off. Chock the front wheels, put both rears on stands, transfer and gearbox in neutral (centre diff unlocked), and turn the prop shaft by hand. Should be able to hear or feel the slightest drag. If you cannot back it off enough to stop any drag and still have a workable handbrake (apply and release brake each time you adjust it), suspect either there is oil in the brake from a leaky seal, or the expander, which is supposed to be able to move with some friction to equalise the shoes, is either rusted in place or free to slop about so that the weight of the mechanism is always resting on the lower shoe. This would be due to incorrect assembly or the spring clip broken.

John

[Brett1066]

Cool, another thing on my to do list....:) Thanks for the info JDNSW, havent tackled this before so all new to me. Gotta do the rear ball joint soon, but any other places that make that goddamn clunking noise that I can fix then I'm all ears.
I think someone (maybe bilbo?) in a previous post on a similar subject said something along the lines of " its all about being one with your car. Some days you are at one and it doesn't clunk. Other days not so good" Bloody true as well. Some days I get very little backlash (well little for my bus) and other days its at almost every gear change and bump.

Sent from my GT-I9295 using AULRO mobile app

[JDNSW]

Anything that allows either axle to move in response to driving or overrun torque will show up as transmission slack. The most common ones are:-

Ball joint on top of axle - usually a resounding metallic clunk when taking up drive (there is no rubber in this joint).

Rear lower link - usually shows up as steering wander with torque, as it will be different each side.

Front of lower link, either the big nut or the three bolts loose - usually a sharp click when going between drive and overrun.

Front A-frame bushes - muffled clunk on bumps.

Surprisingly, in my experience, problems seem to be unusual on the front axle, perhaps because there are fewer joints with much movement. Most common problem there is panhard rod bushes.

John

[AndyG]

Interesting, after my first service, there is a lot more slack in the hand brake, and it seems much smoother to drive, so maybe it was binding.
Mind you a Bas tune also occurred at the same time.
Is not axle flanges fretting out another reason?

[DazzaTD5]

Yes it has been done to death...a search will bring up plenty of results.

Defender 2.4llt TDCi (puma) early ones are prone to the clutch failing which does cause horrific driveability.

after that:
*Axles worn/ excessive factory freeplay.
*Wear in the centre diff side gear shims and incorrect selective thrust from factory.

I've yet to do a Defender TDCi (puma) where I couldnt fix its difficult driveability.

I call all the work a upgrade rather than a repair :P

Regards
Daz

[jabber]

The most common reason for this problem is a dragging handbrake - and it does not have to be dragging much. But transmission slack makes it worse.

John

Had this very issue.... Banging sound when slowing down. Turned out the hand brake drum was "out of true". Ground back to circular and fixed it.

Also had horrible slack in my drive flanges, but replaced them with a heavy duty set.

[Beery]

Thanks Daz.
Is there ever much play in the front and rear diffs?

[n plus one]

Thanks Daz.
Is there ever much play in the front and rear diffs?

Yep, the rears often seem to be badly set up from factory. The fronts seem better (though I picked up a bunch of driveline slack when I snapped the planet gear shaft :p).

[Beery]

Yep, the rears often seem to be badly set up from factory. The fronts seem better (though I picked up a bunch of driveline slack when I snapped the planet gear shaft :p).

Maybe I should go and pay a diff specialist to set them up properly and then send the bill to Land Rover Australia.

[tact]

Maybe I should go and pay a diff specialist to set them up properly and then send the bill to Land Rover Australia.

In order of installation with comment on effect on perceived drive line slack as observed by clunkiness during gear changes and when getting on/off throttle:

- first I fitted Ashcroft ATBs to front and rear diffs (getting them set up by a skilled indie mech in process).

This did seem to reduce drive line clunks - a bit.

Not the prime purpose/benefit of ATBs but inherent design (no spider gears etc) means less slack inside diff centre. Proper setup of R&P also likely a factor in reduced clunks.

- second I installed BAS autobiography tune. This doesn't touch driveline mechanicals at all. But there was perceived reduction in clunkiness due to smoother, finer, throttle control

- thirdly I replaced drive flanges (4) with HD flanges from Ashcroft's. By far! This had the biggest impact with regards to removing perceived drive line slack and related clunks. Seriously thought my whole driveline had been replaced with a Toyota driveline. It actually felt like the term "taut" would not be hyperbole!

Cautions:
- the above comments are about a vehicle that had only 37k km on the clock by the time the flanges were done.
- there wasn't any visible wear on my axle splines. YMMV!
- if you left it longer so that axle splines were already worn, or had more axle spline wear than me at 37,000km then you won't see the same improvement I did
- if you have excessive slop in diffs, driveshaft splines, CVs, UJs, adapter shafts et al: then replacing drive flanges may not give YOU the stunning improvement I experienced
- I have only experienced the Ashcroft gear. Obviously good quality and also expensive! Only saying- maybe there are other brands as good. Maybe some options aren't as tight. So this too may be a variable that could mean you don't see the result I got.

[Beery]

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

[tact]

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

Yes definitely good low speed driveability. A combination of the autobiography tune and less driveline slack. I never get kangaroo hops or shunting.

My normal driving style, whether in a rush or just doddling along, has me take off from a standstill with no throttle. Once moving:
- if doddling I upshift around 2000rpm with minimal throttle openings. No clunks, shunting etc. very pleasurable.
- if in a rush, after a zero throttle take off from standstill, the moment the clutch fully up its throttle to the floor and upshift around 3500-4000rpm. Again no clunks or shunting.

Above works whether taking off in first or second gears.

In the infamous KL traffic jams I just pick a gear and idle along. Any gear from low range first to hi range 3rd ... No shunts etc.

[DazzaTD5]

I've mentioned this in other posts if you have a search but...

I do axle/drive flange change outs on Defender TDCi (pumas) with as little as 10,000KM on the clock because there is already free play in the splines, as 10K is just a trip round the block, it tells me the free play is there from factory.

Add to that the hardness of axles in a Defender TDCi (puma) is considerably less than previous Defender TD5 models (and I suspect as would replacement genuine axles for a TD5). On the rockwell hardness scale the best I've tested a puma axle at was 28HRC, compared to the lowest TD5 (original axle) at 37HRC. The axles out of a puma also readily machine, whereas the TD5 axles are tough and dont machine cleanly.

According to the ones that know diffs and axles, DANA say round 45HRC is the hardest you want an axle, after that its prone to breakage. So the original axles in the TD5 were prolly about right for hardness and toughness.

Once they have been replaced with such heavy duty brands as HTE, all is good, not only is the spline a very tight fit, with the screw on end cap, the outer splines become a easy service item to lube with grease.

Regards
Daz

[tact]

Thanks Neil.
Mine has only just done 10,000km so it's essentially new. I think I might start with the cheapest options first (i.e. flanges) and see what happens. Might convert to oiled flanges too.

So how is your low speed drivability in first and second? Would you call it "good"?

Just re-read your question. My last post waxed lyrical on irrelevant drive conditions and didn't say enough about the relevant one:
Low speed driveability in 1st & 2nd.

In traffic KL jams I can be in bumper to bumper slow speed crawls for up to 3hrs at the worst in daily commute. Good days it's only a 45min trip (35-40km).

As mentioned I usually pick a gear that I can idle along in to keep up and not be constantly stop start. At times the traffic moves a little faster so the job is to feed in a little throttle to close the gap, then back off to idle before having to touch the clutch to avoid nudging the car in front. So regardless the gear I am in its just modulating throttle between idle and 2000rpm for an hour or more.

Have used 1st and 2nd like that for extended periods. Sometimes upshifting from first to second and back again... (To match lane speed).

Really nice and smooth .. No issues.

[Beery]

Thats exactly the sort of feedback I was after. Thanks Daz and Neil.
Good point about the axle steel hardness Daz, disappointing that they're not as good these days.
Is there anyone who makes a heavy duty flange that looks the same as the standard ones? Im just not a fan of the look of the HD ones I've seen.

Im hugely encouraged by your comments Neil. I'll be happy when I can drive in 1st &2nd without cringing every time I get on or off the throttle!

[DazzaTD5]

Is there anyone who makes a heavy duty flange that looks the same as the standard ones? Im just not a fan of the look of the HD ones I've seen.


I did ponder this in thought before posting as I didnt want to provoke any angry responses.... oh hang on that only happens over in the D3/D4/RRS part of the forum :P all good over here in Defender land though!

Hrmm you dont like the look? is it the anodised colour or the hex square end you dont like?? haha if its the colour, once fitted spray some etch primer and paint them black. I assume your 130? has the steel wheels? if alloy wheels then the plastic caps cover the front fine, the rear will just fit, but I machine a mm or 2 off the inside of the cap so the plastic cover clips on cleanly.

Regards
Daz

[Beery]

I did ponder this in thought before posting as I didnt want to provoke any angry responses.... oh hang on that only happens over in the D3/D4/RRS part of the forum :P all good over here in Defender land though!

Hrmm you dont like the look? is it the anodised colour or the hex square end you dont like?? haha if its the colour, once fitted spray some etch primer and paint them black. I assume your 130? has the steel wheels? if alloy wheels then the plastic caps cover the front fine, the rear will just fit, but I machine a mm or 2 off the inside of the cap so the plastic cover clips on cleanly.

Regards
Daz

Yeah heavy duty steels Daz.
Its both the zinc plating and the shape of the hd flanges that im not a fan of.

I can't really explain it, but I've just always been fond of the landy axle hubs, its one of the things that makes the vehicle look good to me.

I wonder if changing to hd axles and keeping the standard flanges would tighten things up.

[Beery]

Good point about etch priming and painting, they should sell them like that

[TimNZ]

Biggest culprit I've found is the intermediate shaft between the main gearbox and the transfer box. On my latest one I had the boxes split, and the splines of the intermediate shaft greased with moly grease when the car was delivered.

I also checked the drive flanges on delivery, only one front and one rear were greased, the other 2 where bone dry and already starting to fret, (with less than 200k's on the clock!) The car has just clicked over 20k, has a BAS tune, and still drives great. (Yes it is noticeably worse with the factory tune).

Cheers,

[85 county]

a bit of missinformation or red herrings posted so far.

forget about hand brake dragging, while not good it is not going to make a drive line sloppy.

1 drive flanges. they a by nature ( good) going to wear so your axels do not. these upgraded heavy duty nut jobs do not have this advantage. Drive flanges never fail IE they do not brake. they wear out and should be replaced and checked and thay are cheep. these HD units i believe will encourage wear of the axle spline not good. how ever if you have ripped the seals out of your front dif and are running oil all the way though i think then they are ok because they will be constantly wet and less likely to leek.

hand brake on hard, jack up one back wheel and rotate. i think 17Deg max. since one wheel is on the ground and one in the air and the pinion is locked by the Hand brake. this is a measure of drive flange spiders and crown-wheel backlash.

BBS, of to get out the bible before i put some one wrong

[85 county]

na 17 deg, some one else can check that out. if more than that then there is some thing a miss.

drop that wheel and pick up a front wheel do the same. but with CD lock in and a bar though a uni or vice grips on the front prop shaft so it will not move, usually a two man. easy enough for a kid or swmbo job.

next frount wheel still in the air cd lock open. hand brake on. turn the front prop shaft. i think 2-3 deg max. more than that next you would check the TFcase end float.

after that put gearbox in to gear, lock TF case, and jack up as back wheel as well. hand brake off ( chock wheels before lifting) now rotate ether drive shaft, again no more than say 5deg movement.

this was good for spotting D1 output splines for fretting, guess that same for the puma, same problem.

that is my no means the only possible issues
a frame ball joint is a common culprit. lower arms bushes same for trailing arms and A arm bushes. again very common. a dif wobbling around between on off throttle give very Simla symptoms.

having every man and hos dog chucking in there suggestions based on what there mechanic told them is not going to work for you.
the only solution is just work though every thing as i wrote above.

then take a bar to your bushes and check them out

[Col 110]

Duplictated Post - please delete

[Col 110]

Getting on the throttle after coasting is painful, no matter how gentle I am. Its just impossible to get a smooth transition from coasting to motoring.

It feels as though the driveline is constantly overrunning and underrunning the engine. And when you reapply throttle it takes up the slack, resulting in the annoying shunt.


What was interesting for me - early on with my drive back from Dubbo I had this feeling - and even wrote it up that changing gears under load was an issue.

After getting home I pulled out onto a busy road and it popped out of high range to neutral - I moved over to the shoulder and after my initial panick of losing all drive I engaged the clutch and pulled the lever back to high range and it really felt like it seated further than what it was i.e. I don't think it was fully engaged!

It is now back to how I test drove it - very little if any drive line slack - loving the way it drives.

I have also noticed that at low rev's (under 2k) it is not happy i.e. choose a lower gear.

1500km clocked tonight and I would say that maybe it is getting a bit better in the just under 2k RPM range for pulling away after backing off.

So - it is fine for me now as it starts to bed down - at 1500km it is still weak in the lower rpm but I do my best to get the right gear for the right speed. I am keeping it 2k - 3.5k RPM and it is doing just fine.

Cheers,
Col.

[tact]

[...]
So - it is fine for me now as it starts to bed down - at 1500km it is still weak in the lower rpm but I do my best to get the right gear for the right speed. I am keeping it 2k - 3.5k RPM and it is doing just fine.

Yeah specially in the early stages (to 16,000km) don't make it struggle hard below 2000rpm. But don't be afraid to get it firmly on boost, with revs over 2000.

Even when it's fully bedded in and running well - be careful of lengthy periods at low revs (1000-1500) with high load and full throttle. (Eg a long hill climb, 5th gear, 1400rpm and foot to the floor just to hold current speed). It's here where exhaust gas temps get dangerously high.

The TDCi engines should try to protect themselves and trigger a reduced engine output event. But surely better to avoid that by a downshift and work it hard with a few more revs in hand.

I have more than 42,000km now on the clock. I reckon it's only in the last 5000km I have noticed the engine has loosened up nicely.

I do enjoy occasional "lazy drives" where I upshift at 2000rpm. But throttle never more than a light caress and rapid progress isn't expected. No complaints, shakes, groans or shudders from the engine.

Remember it's not a big diesel. It will never deliver mega-NM or cruise the highway at 800rpm. ;)

[Col 110]

Yeah specially in the early stages (to 16,000km) don't make it struggle hard below 2000rpm. But don't be afraid to get it firmly on boost, with revs over 2000.

Hi Neil,

I know I have said this over a number of posts - but the best advice I got was from members here that said not to baby it - and also not to thrash it.

I find that 2k rpm to 3.5k rpm range the best for mine - keeps it moving and the gear changes appreciate it. In the towns round here I have to watch I don't end up in 3rd when I should be in 2nd as an example.

Love 1st gear for car parks - seems to go well to coast around and engine brake for speed humps (when you get the timing right).

Cheers,
Col.

[MrLandy]

Mine has just started to loosen up. I noticed a change at around 30,000km, a smoothness to power delivery. I too have always kept the revs up btw 2K-3.5K range. Would be nice if it keeps improving over the next 5K and hoping my fuel economy might improve. My gearbox has loosened too and with no more really cold mornings 1st to 2nd is also smoother.

I'm still a bit concerned about clutch feel though. The pedal feel isn't entirely smooth and confident, there is a bit of crunchiness or roughness felt through my foot when depressing the pedal. It doesn't seem to affect changes, but perhaps it's on it's way out? Any thoughts?

[DazzaTD5]

As a repairer, my comments are generally through observation..

*On a Defender TDCi (puma), the stock axles wear far more than the stock drive flanges.
*Anyone (such as myself) that has done any hardness testing will come to the same conclusion that the TDCi (or prolly all replacement genuine axles to suit TD5 onwards) axles are soft by comparison to axles of old (300tdi axles or earlier)
*at 10,000km I can pretty well say that any Defender TDCi (puma) will have wear showing on the axles and drive flanges, I suspect there is free play already there from factory.
---
*All splines will suffer fretting wear, regardless if they are the splines on the axle or the splines on the hub flange. What has an effect on fretting wear is the hardness of one or both the splines that are in contact, the misalignment angle of the two splines (relative movement between splines), vibration and cyclic rubbing. Also as the fretting wear occurs, the fine particles oxidise which in turn causes more wear (the oxides being harder than the parent metal).
*Lubrication has the greatest effect on reducing fretting wear on splines, the main purpose of lubricating splines is to reduce the occurrence of oxides.
---
*Early Defenders and County models didnt suffer this issue as much (very rare), as there was no axle seal so axle & drive flange splines are kept lubricated by the diff oil, the axles were far harder/tougher.
---

Why I fit "heavy duty" axle / drive flanges such as the HTE (brand) to new Defender TDCi (puma):
*Better quality material in both the axle and drive flange.
*As they are a tolerance fit there is less relative movement between splines (but keep in mind are still considered a floating spline).
*The screw on end caps allow removal and grease to be applied to the inside of the cap, as the cap is screwed on, the grease is forced into the spline area, I do this as a regular service item.
*I wouldnt be replacing axles, drive flanges on new Defender models if I didnt have to, the kits are expensive, the supplier doesnt do a good trade price, if I could buy elsewhere I would (Ashcroft prices are the same, by the time I've shipped to Aust), the price I sell the kit for covers my labour and nothing more, from a business point of view only its a waste of time.
*As posted all over AULRO there are other reasons why Defender TDCi (puma) models do the clunk clunk, faulty clutches on early 2.4, worn out centre diff shims (on the side gears) caused by poor factory setup of the selective shims on either side of the centre diff, the intermediate shaft between the gearbox and transfer case (again another dry spline).
___
Some added things to ponder.
*A longer spline really shouldnt have any noticeable effect on how long it lasts, although fretting along its length will take longer to get end to end.
*Number of teeth on a spline, while its widely accepted that the greater number of splines on an axle seemed to make it last longer, it shouldnt ring true, as in a bigger tooth more load bearing, smaller tooth but more teeth to carry load.
*Old series Landies of old were prone to breaking axles due to poor quality rather than the number of splines used.

All of the above is a rather simplistic explanation, and doesnt do justice to metallurgy or engineering.

Regards
Daz

[DazzaTD5]

Yeah heavy duty steels Daz.

I can't really explain it, but I've just always been fond of the landy axle hubs, its one of the things that makes the vehicle look good to me.


I can...you are odd, only someone that owns a series Landy or has grown up with series Landys could say such a very odd thing...

When I was a small boy (back in the good ol days) myself and my cousin used to stand up in the back of my dad's trayback series 2A Landy while driving through the bush and I did used to look over the edge and watch the "pokey out hub" assembly turning round.

Regards
Daz

[Beery]

Haha, you hit the nail on the head Daz.
Spent much of my childhood either on the bonnet, in the cab, or on the back of the old man's Series 2A swb. Still got the damn thing too. It came with us from WA in the 80's when we moved back east. Along with 2 semi loads of farm gear.

Its something that you cant get out of your blood.

Here's the culprit. Still at work.

https://www.aulro.com/afvb/

[DazzaTD5]

Haha, you hit the nail on the head Daz.
Spent much of my childhood either on the bonnet, in the cab, or on the back of the old man's Series 2A swb. Still got the damn thing too. It came with us from WA in the 80's when we moved back east. Along with 2 semi loads of farm gear.

Its something that you cant get out of your blood.

Here's the culprit. Still at work.

https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-xfa1/v/t1.0-9/10399726_141894399687_4720255_n.jpg?oh=4eb46f4c5b7 d29b9a0dda83008e6d6b0&oe=5694FCE0&__gda__=1456567707_9fb6c533259e5a9bc348e44895988d1 a

Thats gold, here is a pic of me and my first "car" while all my mates were driving LJ, LC Torana's, Ford Escort (cant remember model, the last RS2000 style), and Ford Cortina (again cant remember that model, was the last of the coke bottle style) I was driving a 1978 Series III 88" Land Rover, an ex govt vehicle. I have put it out there on my work facebook page I would buy it back now for top dollar! When it was sold it had a re-built 4 cylinder petrol, weber carb, extractors, 2" stainless exhaust, plastic fan blade, painted bright yellow and was sold to a guy down in Safety Bay.

https://www.facebook.com/aztech4x4/photos/a.448489181890569.103522.378441402228681/448489301890557/'type=3&theater

Regards
Daz