Help! Front diff issues

[Brett1066]

Hi all, driving to work this morning in my 94 300tdi 110 and went to change gears from 3rd to 4th when I hear a horrid grating scraping noise, then the car starts to shudder and it sounds like something is dragging on the ground. :censored: Pull over, look behind and nothing - haven't lost anything off the car. Look underneath and there is steam coming off the front diff.:censored: Managed to put it into diff lock and crawl the last 2km to work.

What has happened? Have I seized the diff? Could it be something else? I have noticed more oil than usual leaking from the big girl lately, and as usual, haven't had time to check it out properly - wondering if I have been losing oil from the diff and today it became critical.

Any suggestions/help/comments greatly appreciated

[steveG]

Whatever the cause, I'd say its broken now if you had to use the CDL to get it to move. If it was seized solid it wouldn't move at all.

Being a front diff its not as easy as pulling half shafts and removing prop shaft to stop it from turning further, and I personally wouldn't be keen on driving it home like it is. If some of the broken bits happen to jam inside when you're moving it could get ugly.

Personally I'd be getting it flat-bedded to somewhere it can be worked on.
Get the center out and go from there depending on the damage.

Steve

[Brett1066]

Yeah I was gonna leave it in the car park at work for a couple of days until I get paid and then get a flat bed to pick it up. I think she might be sitting in my shed for a while.....:censored:

[dfendr]

If its the front diff you can remove the tailshaft and drive flanges lock the centre diff and drive it home

[steveG]

If its the front diff you can remove the tailshaft and drive flanges lock the centre diff and drive it home

Doh! - you're right. I was thinking the cv stub shafts were going to flail round inside the stub axles, but they'll just be static with the propshaft removed.

If the wheel bearings are oil lubed it may get a bit messy though....

Steve

[nismine01]

Without free wheeling hubs the front wheels will still rotate the axles etc, the good side is everything is unloaded, I'd be trying it very slowly and hoping for the best.

Mike

[Michael2]

wow, now you're getting a locker! congratulations.

I know of a couple of people with truTracks at the front (Tdi 110 & D2a) with no issues. Cheaper than an air locker and a DIY on a rover diff,

[Brett1066]

Thanks for the info guys, think I will just play it safe and get the bugger towed. Don't really have the best selection of tools here at work to do much anyway. Will get it home, and then endeavour to pull the diff out and see what the hell has happened.

To try and take a positive from it :confused:, it may be for the best that I park it up in the shed for a while, as I know I have a few other things that need some attention, she's had a hard life (12 odd years in the Pilbara and Kimberley) and needs some TLC.

Don't think it is going to be a cheap exercise though:(

[steveG]

Should be able to pick up a reasonable used center for less than $200, and combined with a day in the shed it's probably all you need to get it mobile again (notwithstanding that you've got other stuff you want to do).

A stronger center is always nice, but if its survived for this long I reckon you'd be right with another one of the same.
Pick up the whole front axle out of a D1 (preferably without ABS), use the center to get you going, and then rebuild it in slow time with additional goodies if you want. Once its ready, pull the old one out and swap the new one in.

Steve

[Killer]

Let us know if it has broken the heads off the crown wheel bolts.

Cheers,
Mick.

[Brett1066]

So, getting the car towed home today....Still have to make room in my shed for it :censored:, but once I have got that done I shall endeavour to find out what has gone wrong and what the damage is. Having never worked on the drive train on this, or any other, car before, any words of advice from the wise people on the forum will be greatly appreciated...

Questions - what tools etc do I need?
What should I be looking out for?
Is it a one person job or will I need another pair of hands?
I don't have replacement parts as yet, figure I will find out what is wrong first, but whilst I am working on it are there any other things that I should replace/service etc at the time?

Any step by step guides/instructions that people know of would be great. I do have the worshop manuals for the car, and somewhere I have the Rave CD floating around - somewhere.

I'm kind of thinking that if I'm going to the trouble of pulling the front diff, I may as well look at checking the whole drive train whilst the car is off the road. I have a rear ball joint that needs replacing - got the replacement part, just haven't had the time or inclination to change til now. Suggestions?

Thanks in advance
Brett

[steveG]

To get the diff center out you need to pull the front axles.
2 ways to do that, either undo the swivel ball bolts that attach them to the diff housing and pull the whole assembly out (apparently damn heavy and I haven't done it that way myself), or on each side remove drive flange, brake caliper, hub, stub, and pull out the CV and axle.
If its been a while since its seen any love then I'd take the second option and inspect/clean all the bits while you are at it (and go a little bit further and rebuild the swivels while you are there).

Once you're at that stage, remove the front prop shaft completely, and then remove nuts around the diff center flange and pull the center out. Center is heavy-ish (20kg++), and its probably a good idea to leave a couple of nuts on the studs while you break the gasket free rather than having it pop off suddenly and land on you.

A-arm balljoint involves a bit of force, large hammer or press and likely some cursing. There should be plenty of tutorials around on that one.

Steve

[BilboBoggles]

Depending how much weight you can bench press, that diff center can be a bit heavy. I used a trolley jack to do a semi controlled descent onto the concrete driveway. Just be aware you don't want to drop it on yourself.

I pulled the swivel housings - they are heavy - but a trolley jack worked really well. Whilst you have the housings off you can replace the swivel seal with ease in case it's leaking. Took me about 1 hour to pull the front diff this way (And I'm slow at this), and also meant I did not feel compelled to replace dodgy CV joints etc etc.

The biggest pain was that I found a damaged UJ. Replacing that UJ took me 4 hours, and 2 UJ joints before I got one in without bending the needles.... I hate UJ's....

[mools]

This may sound obvious but if your going near the rear ball joint - clean the area first. If it's dirty up there (which it will be) it can be unpleasant. I thought if cleaned my vehicle before I rebushed it. Turned out I didn't know the meaning of clean.

Ian.

[Brett1066]

So I managed to get the diff out on the weekend, considering I hadn't done anything like this before it was reasonably straight forward, but not without it's fair share of cursing and swearing. Turns out I have destroyed the two outer bearings - first pic shows one side where the bearings should be, second pic shows the pieces I pulled out of the bottom of the diff housing

http://www.aulro.com/afvb/attachment.php?attachmentid=75412&stc=1&d=1397012807

http://www.aulro.com/afvb/attachment.php?attachmentid=75413&stc=1&d=1397012807


The bearing where the diff connects up to the UJ on the propshaft is quite loose with a fair amount of play, so I expect that was about to fail. Not sure whether I should just replace the bearings, or swap out the whole diff - what have people done before? Am I likely to have done any damage elsewhere? I drained the oil from the centre diff and apart from one small (2-3mm) piece of metal, there was no filings or any other pieces of metal.

[steveG]

Its done a fair bit of work - just bury it with honors ;)
Likely the cross pin is also well worn, along with the holes in the carrier.
A decent second hand center will see you right for a long time and be a lot less hassle and likely cheaper than a set of bearings.

The drain plug in the housing is not right at the bottom, so any crap will collect and not drain out so give it a good clean out prior to fitting the center.
Although by the looks of the debris you pulled out, there probably wasn't much oil to drain. The gunk around the lumps looks like grease - not oil :wasntme:

Steve

[Brett1066]

Spot on Steve - there was sweet FA oil in the diff :censored:- not sure if this was the cause of the problem, or if something else led to the bearings failing:confused:

[steveG]

Spot on Steve - there was sweet FA oil in the diff :censored:- not sure if this was the cause of the problem, or if something else led to the bearings failing:confused:

I'd bet my left nut on it being the cause. Looking back at your original post saying the diff was steaming when you stopped, and the remains of your bearings mixed with a tiny amount of oil confirms it for me.
I'd say its been like that for a fair while too.

Steve