Gearbox/diff output bearing play - howto fix?

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GPW
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Gearbox/diff output bearing play - howto fix?

Post by GPW » Sat Sep 15, 2018 7:46 pm

Hi all, Having just replaced my hubs, wheel bearings and springs...
(Because last time I had a wheel bearing done they bent the caliper carrier getting the bearing out, plus I thought I'd change the top bearings and therefore also the springs as it's been 5 years - plus I had a wheel bearing whine)
...unfortunately I now have found out where the messy oil was coming from on the undertray (and possibly the real source of the bearing whine) - I can see the inner CV joint is oily and when I push the bearing about the gearbox/diff output bearing on the LHS (Short driveshaft) side has some play in it.

The gearbox itself took around 0.75L of oil and I can drive it around for a bit longer but I really need a fix in the medium/long term.

So is this a gearbox out job? Has anyone done this before? Is it at all DIYable?
It almost looks like the diff housing can come apart in situ but I suspect that's me just dreaming and it won't be that easy at all.

Thanks in advance!
Average home mechanic in Cambridge, UK. Peugeot 406 1998 1.9 tdi GLX

jasper5
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Re: Gearbox/diff output bearing play - howto fix?

Post by jasper5 » Sat Sep 15, 2018 10:42 pm

You still have a whine after replacing the wheel bearings?
A proper diagnosis would have helped.
Is the leak not related to a bad oil seal?
Most leaks from the inner driveshaft are related to the oil seal leaking (use genuine seals as the non genuine ones don't fit very well!)

Regarding the diff...it can be removed as it is bolted onto the gearbox...whether it's a diy job depends on your skill level and if you have room to lift up the car high enough.
You will need to remove both driveshafts and the rear engine mounting and mounting housing block.
It might be easier to remove the whole gearbox and replace it as a second hand unit...it will probably cost less too.

PeterN
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Re: Gearbox/diff output bearing play - howto fix?

Post by PeterN » Sat Sep 15, 2018 11:48 pm

Make sure the shaft is pushed right in, I believe they have snap rings to locate them.

Peter

GPW
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Re: Gearbox/diff output bearing play - howto fix?

Post by GPW » Sun Sep 16, 2018 9:34 pm

Hi all, thanks for the replies.

I'll check it's pushed all the way in, do I just push the driveshaft toward the diff to make sure it's fully in? I thought as they were prone to falling out on their own they just pressed in?

Now I've got two new wheel bearings and some more oil in there I'll take it for a test drive to see if it still whines - just waiting for new nuts for the steering ball joints so should be later this week.

The play I felt is up and down (vertical - it moves up a bit when pushed on the bottom. Should there be any vertical play on the bearing? It feels like about 0.5mm. I'd like it to just be the seal - I guess if it doesn't whine a new (genuine) seal is the first thing to try?

Sounds like a new seal is done on the car (dig the old one out, press the new one in?), but if it's the bearing it's a case of dropping the gearbox out thn:
a) unbolting the diff and replacing the bearing with one of the right size or a Peugeot part from a dealer.
or b) Bolting in a gearbox from a scrapped car.
Average home mechanic in Cambridge, UK. Peugeot 406 1998 1.9 tdi GLX

jasper5
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Re: Gearbox/diff output bearing play - howto fix?

Post by jasper5 » Sun Sep 16, 2018 11:16 pm

Peugeot Citroen left hand side driveshafts are only a push fit...you should always take care when lowering a ball joint or moving the hub on the left side as the driveshaft can just drop out from the gearbox leaving a nasty oily mess from the loss of gearbox oil.
I can't remember which side has the oil seal housing bolted on by 4 bolts but I think it's the left side...take off the housing and replace the oil seal.
It isn't really unusual to find a little bit of play up and down in an inner driveshaft, of course there are limits!

When you heard the whine was it constant or only when you put the power on?
A diff bearing noise is usually apparent when the power is applied after coasting whilst a wheel bearing noise tends to be constant, especially when the car is out of gear and freewheeling.

GPW
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Re: Gearbox/diff output bearing play - howto fix?

Post by GPW » Mon Sep 17, 2018 10:40 am

Thanks for the info, I'd taken care that it didn't fall out when I had the strut out by sticking a big (#3 philips) screwdriver through the lower wishbone hole (where the lower balljoint bolts in) and wiring the driveshaft end that used to sit in the hub to the screwdriver handle with some spare zinc coated garden wire.

The whining was constant and worse on one direction of corner (can't recall which), so I was reasonably confident of a wheel bearing going.

I wanted to replace the bent 'swivel pin' castings anyway (that needed 1mm washers between hub and caliper carrier to stop the calipers touching the discs since the last wheel bearing change by a garage) and wanted new top bearings in there so the whining sound was just a prompt to get on with the mini-overhaul.
Got the swivel pins from eBay at a good price and they fitted pretty well, the only difference is the square pinch bolt head needs a spanner now as the grinding on the new one no longer locks the heads - but that's a small detail, everything else bolted right on - parts 364642 and 364742 FYI.
At least it's nice and straight now LOL and I know all the nuts turn. Brakes feel good too as everything is now straight.

As an aside I also freed up the pistons nicely: drained, popped closed onto some wood (to restrict piston travel) with an air line and pulled back in (hand trigger operated wood clamp if stiff) to make sure they were both moving freely - not long since I cleaned them out anyway. The trick to getting the pistons back in under the bellows (last time when I took them out) was found to be some compressed air and some wood, the bellow literally blow themselves out over the pistons like a balloon. I hate dragging brakes. The trick is to use some wood and not lose any fingers :). Also when re-installing empty pistons the gravity from the reservoir bleeds them as there's no airlock, or at least it did on mine...

Fingers crossed the whine has gone and I just need to do the seal, will report back: I'm not brave enough to re-use the old steering knuckle nuts as I had to grind one off (They are fine pitch M10 x 1.25mm).
Average home mechanic in Cambridge, UK. Peugeot 406 1998 1.9 tdi GLX

GPW
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Joined: Fri Sep 14, 2018 11:30 pm

Re: Gearbox/diff output bearing play - howto fix?

Post by GPW » Sun Sep 23, 2018 12:51 pm

Just an update to this, I decided that after the advice on here I'd treat the small play as 'within tolerance', so I just replaced the oil seal and put some new oil in, then if it's fixed I won't have to do anything else to it.

The oil came out clean too as did the sump plug so I'm hoping for the best.

The oil seal was pretty easy in the end as I undid the lower balljoint (popped apart with a G-clamp, crowbar and bit of wood so I could leave the brake in place - worked perfectly), loosened up the 3 top strut bolts, popped off the hub nut and just moved it aside to pop out the driveshaft.

Popping the old seal out was easy with the crowbar used carefully and the new OE one went in nicely with a bit of oil and a flat press disc tapped in, reassembly was the reverse of removal with a bit of oil over the seal to keep it happy.

So fingers crossed.
Average home mechanic in Cambridge, UK. Peugeot 406 1998 1.9 tdi GLX

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