Daihatsu diesel conversion problems

[Tim Jones]

Hi, I`m on the west cost of SA near Elliston.....I`ve been reading AULRO forums for a while to help me out of the mire I get myself in so I thought it was about time to sign up. So.....18 months into a Milner Daihatsu diesel conversion into a series 3 ex army I`m having gearbox trouble. I rebuilt the box (mainshaft, bearings and a new but stored for ages 3/4 synchro:eek:) and also put a high ratio transfer case in while I was at it. To my amazement it all worked......for about 4 days. It started jumping out of fourth but only under heavy load (foot flat down) Total devastation:( It seems to be getting worse (jumping out with any revs) though I`m not driving it much at the mo....I`ve got some new synchro springs coming but I`m suspecting a misaligned conversion plate that ate the transmission in the first place after reading a thread in the holden engines section. The only other thing maybe is that the clutch sat around for a while and has some rust between the plate and the friction material so is not dead true but engages smoothly. Any ideas anyone before I pull it all apart again?

[Blknight.aus]

no you've pretty much nailed it.

the S3 box that only jumps out of 4th has most likely done the input bearing and will be taking out the center support bearing for the output shaft.

if its jumping out of 3/4 then it can be a combo of the syncro gear, selector forks and the bearings.

[Sitec]

Just reading the words Daihatsu gave me the shivers! Before the box started to play up, how did it go? Milners are usually pretty good. I'd be surprised if they had the conversion ring out of line... How easily did the gearbox go onto the engine when you assembled it?

[Tim Jones]

Thanks for the replies.....it jumps out of 4th under load I`ve only done about 40km for fear of destroying it again:o but the input shaft bearing still sounds quiet with the clutch in out of gear (quieter than the engine anyway). I`ve realigned the selector fork on the shaft (centralised) and grasping at straws put in the transfer box detent plunger with a reverse gear spring (not much change). It was a bit of effort to get it in originally but I thought maybe it was just a tight spiggot bush (far to excited to do anything about it) but in hindsight I`m hearing alarm bells. Also the clutch had a rattle that ended up being the splined centre being loose (that wasn`t before)......Also the old synchro was very worn even with a spline missing and it was getting a bit of a worry driving it anywhere far(!) The plate does seem well made I was impressed when it arrived but then again milner isn`t milner anymore from the point of view of conversion kits.....by the way whats up with daihatsus I`m loving it (or was) 15000ks on vegetable oil! Thanks guys what do you reckon

[Blknight.aus]

you could try shifting the 3/4 selector a little towards 4th, if this fixes it then the selector fork is worn, or something is not setup right in the syncro/shaft alignment.

[Tim Jones]

I tried it and can feel the detent spring engage and then go past a tiny bit so its definately engaging......I`ve got some new synchro springs coming (The replacement synchro was stored for ages (judging by the dust I got it in a heap of other spares) but appeared unused, certainly hardly at all, no wear on the splines, but I would`ve thought they would jump out on the overrun first???'so I`m thinking I`ll offer the bell housing up when its off the gearbox that should give a clue as to whether the alignment is out......
Glamourous, isn`t it.

[Blknight.aus]

yeah, this is one of the reasons I dont like working on gearboxes on conversion series.

have you tried seeing what the 4th gear selector set does when you dont have the selector mounted on its shaft?

[Tim Jones]

Yes I had a go at that thinking maybe a spring had broken or something but as far as I could see it was doing its thing, moving far enough etc. Does the selector shaft detent do most of the holding a gear in or the synchro detents?Though I`ve never had a properly working one in my hand, I wondered if the action was a bit light (hence the new springs)......Its helping me out talking about it anyway...hopefully I won`t lie awake at 3am tonight......!
At least I think I know how a synchro works now......

[Tim Jones]

Update.......I took the gearbox out today and bolted a bit of angle onto the flywheel face and rotated it....sure enough the ring seems to be sitting about 1mm high. I didn`t have time to try the parallel measurement. I also tried levering the flywheel (gently!) up in case the main bearings are worn but I would`ve thought 1mm would be pretty excessive. Any thoughts on whether this could be an issue before I get the file out, or if levering with a foot long tyre lever would be sufficient to see any movement in the crank?

[Bearman]

Tim, it's been a long time since I played with a series box but I can remember a similar problem occuring if you put the 3/4 synchro unit in back to front. I remember it fits in both ways but will jump out of gear but I thought it was on 4th overdrive not under power.

[Tim Jones]

thanks bearman I reckon I did it right but I`ll find out tomorrow...

[Tim Jones]

update.......The plate was out by 0.012mm but only up and down (?) the plate was parallel. I managed to get it down to 0.004mm by carefully filing the dowel holes and plugging with locktite and epoxy putty. Anyone reckon this is close enough? The crank has a bit of play like 0.005mm up and down I`m thinking this isn`t helping...any thoughts?

[Blknight.aus]

ok first off, are we working in thousandths of an inch or in mm? if in mm you must have a very very fine set of files as you're working on a finer tolerance than my verniers.

assuming its in thousandths of an inch

thats more than close enough, its probably better than OEM specs.

whats important now is to see how the play on the shaft goes and to see if you can replicate the box jumping out by operating the box by hand.

if you have too much float on the support and input bearing for the input shaft you'll get jumping out of gear any time theres enough drag on the output shaft that tries to pull the shafts apart

(have a look at the angles on the teeth, + remember the layshaft is always driving)

[Tim Jones]

Phew! I` was beginning to think I should go and juggle it again.....I`m going to fit the bellhousing and input shaft alone and perhaps try and measure how square the rear of the input shaft in relation to the rear face of the bellhousing, I`m thinking this should be dead on otherwise it will wobble it out of 4th? I`m also assuming that the crank float will be forced down when the engine is running but then again maybe some weird gyroscopics are going on. I centred the adaptor by taking up all float before measuring the eccentricity (the adaptor not mine)
There`s a little play in the input shaft when the box is assembled, no oil leak (amazement) and all the bearings were new 80km ago so they should be OK. I`m not sure about inspecting the 3rd and 4th female splines (on the 3rd gear and input shaft) They look a tiny bit tapered but also look like the steel is harder than that on the synchro hopefully saving them....I have a spare input shaft but it looks identical.....
Thanks Dave your advice is much appreciated (and everyone else...)

[Blknight.aus]

worry less about the movement on the spigot side of the input shaft and more about the back and forth movement of the shaft in the box.

remember that the input and out put bearings cantelever off of themselves on the center support bearing as well as get their "preload/endfloat"

a lot of movement on the spigot side of the input doesnt equate to a massive amount at the center support bearing and its more of a problem if the input shaft is running "off center" which it appears yours isnt. My next line of thought is that when the box is running the various thrusts being created from the input shaft, the lay shaft and the output shaft is enough to cause the 4th gear syncro to disengage enough to allow the baulking ring to throw it back out of gear.

[Tim Jones]

Just been out to the shed in my PJ`s seems like no back and forth movement, a little on third gear which measured fine when I replaced the distance piece. The thrust washers were within tolerance. I replaced the rear bearing (in the transfer box) but not he outer race (couldn`t work out how to get it out and it looked ok) I can`t feel any wobble in the shaft (its engaged in the input shaft). The layshaft has no endfloat either...
By the way I thought I was in mm but my feeler gauge has no units(!). I used them with a bar bolted to the flywheel to compare clearances and tried to get spot on but settled with much better than before...

[Bearman]

Did you check the synchro unit to make sure it is the correct way around while you have it apart.

[Ancient Mariner]

I would go with that

[wrinklearthur]

I once had a centre PTO ( it fits on the back of the transfer box ), it had a fault causing the gearbox to jump out of 4th.
I put the blanking plate back on and the problem went away. Look at the bearing inside that blanking plate.
So that backs up what Dave has said about bearings.
You haven't got a wrong size bearing some where ?

Can you tighten up the thrust washers in the engine? as any increased crankshaft end float could be moving the input shaft to and fro a fraction, walking the 4th gear coupling apart under load.
I have had PTO's on tractors disengage when the implement's drive shaft hasn't been sliding freely and again it was causing the coupling to walk apart, with the transfer of the fore and aft movement into the PTO dog clutch.

Double check the linearity of the centre line of the crankshaft to the centre line of the gearbox mainshaft, as any slight tilt at all of the input shaft will walk that coupling apart .
.

[mick88]

Just reading the words Daihatsu gave me the shivers! Before the box started to play up, how did it go? Milners are usually pretty good. I'd be surprised if they had the conversion ring out of line... How easily did the gearbox go onto the engine when you assembled it?

Interested to know why the word "Daihatsu" gave you the shivers!
I have been considering using one for a conversion.
Have you had a bad experience with them?

Cheers, Mick.

[Tim Jones]

Yep the synchro was the right way round....Interesting, the rear bearing housing is off a different box (also series 3) I might change it back.....I`ve just re checked the alignment and yes I was working in Thousands of an inch (spot the novice) and have now got it to 0.001 which I`m happy with. Now the quirky bit, I offered up the bellhousing expecting it to slide on but its stiff. The spiggot bush is in an adaptor in the flywheel (pressed in) (ok whacked in) As far as I can measure it, it is in square, but the input shaft is suggesting its not. Surely the bell housing can`t have distorted? I just want to clear this alignment thing up before going further.....It does seem to agree with Arthur also if the input shaft is off centre making fourth walk out especially under heavy load. Yeah I`m getting the shivers a bit too....

[Tim Jones]

Better just add its got a just fitted ashcroft high ratio transfer box....Just to open another can of worms though I can`t see that the rear bearing housing could be in a different spot.

[Ancient Mariner]

If you havent got a dial gauge I would suggest you buy one. Bolted to the flywheel you can check for any misalignment and if parralel .Not that dear and heaps of other uses as well

[Tim Jones]

I`m gonna

[Blknight.aus]

ahh the dreaded long shaft droop..

check the centering of the input shaft in the bell housing relative to the studs then do the same for the spigot bearing inside the flywheel.

I bet that you'll find the input shaft on the gearbox has dropped down 1-2mm and is just not quite jumping in when offered up and is dragging the splines.

If Im in doubt as to a spline/spigot alignment issue I pull the box out remove the clutch and do a dummy up with the inspection port on the top of the bell housing (metal plate under the gear lever ball mount) and have a good look at whats actually happening on the spigot rather than trusting numbers. Its all too easy to mix up the measurements when your turning back and forth.

[Tim Jones]

Rightyo progress...... I offered up the bell housing and input shaft alone. Too tight. Hmm studs misaligned? No I checked them. Remove them anyway, shaft slides in nicely but the housing is 1/2" skewed. Pullit off again wobble the spiggot bush adaptor with a spare shaft pop out it comes. As a bonus it looks like the adaptor to flywheel joint has been performing the role of spiggot bush and spinning. Still a tightish fit when fully in so I tapped (no whacking this time) it back in with a drift and put the bell housing back on....sweet. Now for the Land rover bush job. I loctited it in place with the input shaft and bell housing fitted and have left it to cure overnight. Tomorrow I`ll turn it over on the starter with a bracket alongside the fourth gear synchro cone and see if there`s any wobble, if not I`m planning a little liquid steel around the perimeter of the bush adaptor, not so much to hold it in place but to stop it from walking its way out of the flywheel again. I havent many other options right now as this is our only car and the nearest suitable machine shop is 200km away....It`s looking like the culprit as a result of the misaligned plate binding up the bush adaptor and spinning it loosely in the flywheel the input shaft must`ve been all over the shop. It feels really smooth now in place. I will be checking the input shaft centralisation though......

[Blknight.aus]

Dont use the liquid steel if you have the choice... hit on something out of the loctite 600 range

Loctite ® 620 (http://www.loctite.com.au/3423_AUS_HTML.htm?countryCode=aue&BU=industrial&parentredDotUID=productfinder&redDotUID=10000009RF0)

638,648 and 620 would be the best bets, 680 and 690 would also work if A, you can get them and B, you dont want to take it out with hand tools again.

[Tim Jones]

Heres another update......I got the spiggot bush straight by drilling and tapping 3 holes in the addaptor and screwing in allen headed grub screws (out of a surfboard!!!!) that I could turn to centralise it, measuring with feeler gauges. It was handy having the bell housing separate so I could wind the engine over on the starter to see if there was any wobble in the input shaft. Initially there was, but now nothing is visible though I didn`t measure it. It`s definately way better than it was. While the bell housing was off I tried wobbling the end of the mainshaft, a tiny amount of movement but I thought not enough to worry about. So it all went back together (synchro the right way round). I haven`t driven it yet (still putting fiddly bits back on) but 3rd and fourth still don`t really feel like they`re locking in positively, certainly not as strongly as 1 and 2. Is this normal? The detent recess in the shaft is not worn, and I have a reverse gear spring in there, and did all the jiggling to line it up right. Anyone tried deepening this recess slightly? Still I`m feeling marginally more confident this time........

[Tim Jones]

Here`s my latest theory....I`ve worn the splines inside the input shaft and although the engine is aligned now, the now tapered splines are still forcing 4th gear out. Is this possible or is it more likely the play in the crankshft (0.005")? It`s doing my nut a bit!

[wrinklearthur]

Hi Tim

I would be asking if there is a difference with the synchromesh rings, between a 2A and the S3, you may have the wrong one.

As for the coupling teeth, it would not had time to wear a taper, but it may have marked the leading edge.

Undo the bolt in the selector fork on the selector shaft and see if you can push the selector fork further along the rod into the 4th gear position.

Now you have me curious, I will stick my nose into the workshop manual and see if I can work out anything else that would prevent the 4th gear engaging .
.

[Tim Jones]

OK yes I did wonder about the synchros but it appeared identical to the one that came out and the other series 3 synchro I have. I did about 15000 ks with the out of alignment engine, and I`m assuming the synchro was original (I haven`t replaced it before, 15 years ownership) The old synchro was really damaged, the teeth were like knives almost and one had broken off so there was some decent forces happening in there, it looked like a no brainer! I did the selector shaft thing, and as far as I could tell with a torch the splines were engaging fully with the coupling teeth. Funny thing is it doesn`t feel any different at all, perhaps a little less whine (which wasn`t much anyway). I`m considering filing out the detent groove in the shaft as I have a spare selector, but I can`t help thinking I`m fixing a symptom, not the cause, so I`m hesitant....

[Tim Jones]

Hi everyone heres another update....I ground out the 3/4 selector shaft detent locator with a burr and drove 10km. Seemed all fixed. Couldn`t help wondering if it had fixed a symptom. Drove 10 ks again this time flat out(!) up a hill, yes you guessed it it popped out, but only once the load reduced a bit. I also noticed (and with hindsight I reckon it was there louder before I realigned the engine) a sort of worn diff whine noise coming from the gearbox before it pops out. Could it be the input shaft teeth working their way out? I`m down to worn input shaft teeth, or too much play in my engine crank bearings.....It`s looking like the input shaft first, a bit more in my league. I`ll just get my wallet.....

[Tim Jones]

Rightyo touch wood I think its fixed......seems like the input shaft teeth had just enough wear in it to pop it out of fourth. I put in a new shaft and bearing and crossed my fingers. Even with the high ratio transfer case with my foot flat down labouring uphill I couldn`t make it jump out. It`s still got the ground out selector with transfer case detent plunger though (I wanted everything going my way!!!) It does seem that the HRTC does put a lot of extra stress on the gearbox, its tempting to stay in fourth and grind away but I`m thinking that is a quick way to damage it again. We`ll see how it holds up on a longer trip this month......look out Flinders ranges. Thanks to everyone who had an input, I really appreciated the interest and advice, no doubt it won`t be the last time.....

[Tim Jones]

Just one quick P.S. It all seems Ok except it just jumped out of third on the overrun, obvious really the teeth inside the third gear must look similar to the worn input shaft (I didn`t look). Just in case anyone`s reading this with similar problems, consider replacing third also if the teeth are worn (tapered), or the synchro has been really worn (like mine was but not as bad as the fourth gear side).....If you are reading this I`m feeling for you....

[dickyjoe]

Hiya Tim,

Just skimmed through this post. How is it all behaving now? Is the gearbox going ok now? How does the diesel and high ratio TC match? How is the drive ability?

I always thought the Daihatsu non turbo 2.8 diesel would have been a good fit to a Series LR. About the same power as a 2.8 Hilux and an engine that can cop a beating. We had one in a Rocky ute and it did heaps of work onroad and offroad and stood upto it without an issue.

Ended up trading it at about 350,000km and it was the body of the car falling apart not the engine. Sure the injector pump probably needed servicing and the glowplugs and injectors needed replacing but it kept on going and going.

Richard

[Dinty]

I did my own conversion using a Daihatsu N/A 2.8lt in my Series 3 station wagon around 1991, it went very well, yes it used to pop out gear on occasions but I did make my own conversion plate, I do have some Polaroid images of the job somewhere and I still have the full size drawing of the conversion plate somewhere, anyway cheers Dennis
ps way back in the early 90's (last century) I also had trial fitted a Isuzu diesel (ex Gemini car) into a Suzuki chassis, very neat fit, but I gave the idea away because I didn't think the engineer would pass how I had re-routed the Oil cooler etc,,.

[fourteen8]

Does daihatsu diesel engine is direct fit or you need to chop the chassis to fit into Series 3?