E85 Diff finally given up so what to do next?

[Armscarf]

Folks,
I’d welcome some thoughts on this one.

I have a 2004 2.2, recent MOT, reasonable spec in Maldives Blue, I would guess it’s worth £2.3 - £2.8K in full working order. see this post. https://z4-forum.com/forum/viewtopic.php?f=11&t=123443.

As I suspected the rear diff is very much on the way out, this is not a surprise so I’m cool with it. I have considered these options:

1. Get a BMW specialist to fix it – I’ve been quoted around £2K for the job, clearly that’s not a sensible option on this car. The Diff alone is £1300 + VAT. (P J Autos in Hanley)
2. Source a second hand diff (about £300) and see if I can find someone to take the work on – I’ve already been turned away from my local garage as they seem to concerned about the job.
3. Fit a replacement diff myself – I have the skills and most of the tools I need but no access to a ramp. This would be a weekend undertaking and fiddly to say the least but I haven’t ruled it out yet. No point in hiring space on a ramp as the costs then creep back up to just getting someone else to do it.
4. Sell the car as-is for spares and repairs – serious offers welcome, Forum Members only
5. Break the car myself, keep the bits that I might need, sell what I can and then scrap the rest.

Any thoughts and suggestions welcome, I’m genuinely not sure how to tackle this one.

Thanks.

 

[Wookster78]

If I were you I would have a go at changing out the diff yourself for the money involved. I did it last year having bought a secondhand diff from eBay at a higher ratio for £70, cleaned up the casing and replaced all the seals and new fluid. Luckily I have a hydraulic lift which is the essential part as it is actually pretty easy to swap out with basic tools unless you are also changing the rear diff bush as you need a Bush puller to get it out. Tricky part for you is getting it in the air to gain access. Maybe you can hire or purchase a scissor lift which would be useful but if kit for the future?

Something like this should work:

https://www.ebay.co.uk/itm/264835059808

 

[Armscarf]

[ref]Wookster78[/ref], Thanks for the reply, I'm warming to the idea slowly. I have a more specific question for you, I have some of these, can you see an issue with the height of these or the angle of the car when I need to lower the diff onto the trolly jack?
https://www.manomano.co.uk/p/2x-car-ramp-hydraulic-lifting-jack-device-ramp-adjustable-2t-garage-bottle-jack-6752702

 

[lucasxdiniz]

I removed my diff a few months ago in 5-6hrs with the rear raised with a 500mm raise jack. It was perfectly doable.

The photo suggests how high the rear was lifted up.

 

[Wookster78]

Yeah I would think those should do the job, clearance is not an issue as it should come out at that height it’s only the manhandling of the diff getting in an out that’s the issue, with two people shooting shout be fine, I used the extra room for a transmission jack to take the weight but you can manhandle it adjust need some spinach before

 

[Silverstar]

2K, is that for a brand new diff? a few years ago my E46 diff was whining and I had it rebuilt by a specialist for less than £500. I kept the car a good 10 years after this and had no problems with the rebuilt diff. Wouldn't that be a more cost effective option (apart from fitting a second hand one yourself)?

 

[Armscarf]

[ref]lucasxdiniz[/ref], Thanks, really useful and most excellent pooch

 

[Armscarf]

[ref]Silverstar[/ref], Yep, it seems that P J Autos only do genuine parts hence the price, and that didn't include the trans' oil. I was disappointed that they thought a new one was a reasonable option for that car. That said the car is under a limited warranty so I guess they thought the £500 from that would encourage me to shell out the remaining £1.5K

 

[GuidoK]

A 2nd had diff should be far less than 300,-
I've bought a 2nd hand one for 80 quid and a 2nd hand one for 125 quid. (both 3.0 diffs though).
Swapping a diff should be doable for an independent garage in 4-5 hours, so maybe 250 on labour. I think I can swap mine in under 2,5 hours (past problems made me very experienced with this )
The only difficult thing is that ideally you want to remove the exhaust system. Those bolts on the front (where it meets the headers) can be a pain if they've never been removed before.
Maybe it can be done with partially lowering the exhaust, but I always take mine off completely.

The only thing to consider is whether or not to replace the input and output seals on the diff before installing or not.
that can be a bit tricky if someone is not familiar with specifically bmw diffs.

 

[PDJ]

The way I would go about this would be assuming it is not your only car

Remove diff yourself

Get it to JC Racing in Thirsk for repair assessment on repair option

Look for a second hand one

Fit which ever option into the car

Diff removal, it is held in with 3 bolts, the input shaft and the 2 output shafts and whatever else is in the was ie exhaust under trays

I changed mine Z4M on my own with the car on stands a trolly jack and a large does of determination.

 

[Armscarf]

Thanks again folks, it seems the fix it myself option is the way to go. Just for clarity on a couple of comments. It's my 3rd car so it can sit on stands as long as is needed. The £300 approx was for a re-conditioned diff with a warranty. I guess the next thing to do will be to have a deeper dive into the best place to source one.

 

[Armscarf]

Update on this one folks, I've ordered a recon diff with warranty, delivered to my door next day for £270. So I'm prepping for a weekend in the garage Thanks to all those that replied, I think we arrived at the right solution.

 

[Wookster78]

Good luck, tip don’t need to remove the whole exhaust to do the job just the rear and central mounts, support it on whatever you can and there is enough room to get the diff in and out. Bolts on the exhaust flanges if not taken off in a while/ever can need drilling out and it’s a sod of a job

 

[Armscarf]

[ref]Wookster78[/ref], Just as well as I already know that the bolts to the manifold section are very rusty.