4.1 Diff fitting options

[AndyBeech]

So I've just managed to bag a 4.1 gear set after deciding it'll be my 'big' mod for this year, been tempted for a while but saw the gear set on Ebay for £695 from BMW so decided time to bite!
(Well worth keeping an eye on Parks Motor Group, part number: 23008437087 if anyone ever fancies it, by far cheapest I've seen it sold new, seems to come up now and again for sale).

In terms of fitting, anyone got any particular recommendations for places to have it done as well as what else to replace at the same time?
I'm in Wiltshire so good choice of specialists, Redish and Everything M3's being the obvious choice having used them both before. Anyone else worth considering as I suspect they both have long waiting lists for work as usual.

Anything else worth replacing while the job is being done? Car's on 105k miles. Redish recommend driveshafts but this seems a bit overkill to me?

Much as the Redish 'rebuild' option sounds good, not sure I want to pay 2k when I don't think I've got any particular issues with it currently.
Yeah so any advice appreciated!

[Simon 3.2M]

Will you be building this into your existing casing Andy or is it actually a new diff?

[AndyBeech]

Will you be building this into your existing casing Andy or is it actually a new diff?

Into the existing casing

[beanie]

I could see the sense in stumping up for subframe bushes from a ‘whilst most of its apart’ perspective but driveshafts seems OTT. Pricey as well.

I think I’d be tempted to do the diff mounts (no brainer imo) and flex disc and budget for the possibility of the center support bearing if it’s worn. Rear camber arms are a fiddle to change with the diff in place so perhaps it’s a good excuse to do those as well

[lucasxdiniz]

Hello,

I’ve got very recent experience with this very thing. I doubt it will come back at the same price, they had 7 in stock which have all sold over the last few months. I bought no 6. I had assumed it was old stock due to the price, but can confirm it is all genuine!

As for fitting it, it was cheaper for me to pay Dave Heasman to set it up for me than to buy shim kits. He’s got a good reputation from the M3 forums and I was just with him on Friday getting the diff built back up. Excellent chap. Happy to share more details in private.

[AndyBeech]

I could see the sense in stumping up for subframe bushes from a ‘whilst most of its apart’ perspective but driveshafts seems OTT. Pricey as well.

I think I’d be tempted to do the diff mounts (no brainer imo) and flex disc and budget for the possibility of the center support bearing if it’s worn. Rear camber arms are a fiddle to change with the diff in place so perhaps it’s a good excuse to do those as well

Cheers beanie, done a few of those already so will look into it

Hello,

I’ve got very recent experience with this very thing. I doubt it will come back at the same price, they had 7 in stock which have all sold over the last few months. I bought no 6. I had assumed it was old stock due to the price, but can confirm it is all genuine!

As for fitting it, it was cheaper for me to pay Dave Heasman to set it up for me than to buy shim kits. He’s got a good reputation from the M3 forums and I was just with him on Friday getting the diff built back up. Excellent chap. Happy to share more details in private.

Ah you got one as well! Yeah price seems very good, too good not to almost! I was only looking as there was a chap selling a second hand but new one on the Cutters forum for £800 odd, nearly sent him an offer when I saw the Ebay one on the off chance. Seems like there's another BMW dealer selling them even cheaper but...happy with what I paid.

Funnily enough spoke to Dave this morning. Seems good so will probably sort something out with him. Sadly not good enough with the spanners myself to get the diff off so not sure how I'll sort out the logistics at the moment. Shame doesn't offer a drive in drive out service but obviously that keeps the costs down. I'll drop you a PM

[Beedub]

So I've just managed to bag a 4.1 gear set after deciding it'll be my 'big' mod for this year, been tempted for a while but saw the gear set on Ebay for £695 from BMW so decided time to bite!
(Well worth keeping an eye on Parks Motor Group, part number: 23008437087 if anyone ever fancies it, by far cheapest I've seen it sold new, seems to come up now and again for sale).

In terms of fitting, anyone got any particular recommendations for places to have it done as well as what else to replace at the same time?
I'm in Wiltshire so good choice of specialists, Redish and Everything M3's being the obvious choice having used them both before. Anyone else worth considering as I suspect they both have long waiting lists for work as usual.

Anything else worth replacing while the job is being done? Car's on 105k miles. Reddish recommend driveshafts but this seems a bit overkill to me?

Much as the Redish 'rebuild' option sounds good, not sure I want to pay 2k when I don't think I've got any particular issues with it currently.
Yeah so any advice appreciated!

changing driveshafts is imo an absurd thing to suggest unless they actually need replacing ( not something ive read about on the E85/6 being a weak spot.... Cant lie, my thoughts of reddish were somewhat tarnished a few years ago with my stuck shim issue. i REALLY like the way they work and their workshop setup , but they got one of my visits hugely wrong and if id have gone their route it would have literally costs me ££££s for no reason, i drove the car home and sorted it myself for under £200 quid. At the time i couldn't help but feel like weren't quite for the "people" and i haven't been back since. Admittedly..... This was an isolated thing that they'd never seen before so as the years have passed id like to reunite with them and see if we can right that wrong. My circumstances changed and i ended up with my own workshop properly tooled up so i started doing most of it inhouse to keep the quality where i wanted. Its only the really specialist bits i will now send the car out. I'd try simpson motorsport, hack engineering also.

[PDJ]

If you can get the diff out at a local garage as that bit is only heavy and a finger/hand trap you could send it up to JC Racing up North in Darlington he does quite a few and does them for other BMW specialists as well as race teams

He serviced/rebuilt my diff turned it round in a week I dropped it off and collected as I had my other car to do that

There is always Mr Vanos but he could just get JC to do it there are only a few miles apart

There is a ball bearing in the diff that needs to be spark eroded to get it apart so not that many people actually do it themselves

[AndyBeech]

changing driveshafts is imo an absurd thing to suggest unless they actually need replacing ( not something ive read about on the E85/6 being a weak spot.... Cant lie, my thoughts of reddish were somewhat tarnished a few years ago with my stuck shim issue. i REALLY like the way they work and their workshop setup , but they got one of my visits hugely wrong and if id have gone their route it would have literally costs me ££££s for no reason, i drove the car home and sorted it myself for under £200 quid. At the time i couldn't help but feel like weren't quite for the "people" and i haven't been back since. Admittedly..... This was an isolated thing that they'd never seen before so as the years have passed id like to reunite with them and see if we can right that wrong. My circumstances changed and i ended up with my own workshop properly tooled up so i started doing most of it inhouse to keep the quality where i wanted. Its only the really specialist bits i will now send the car out. I'd try simpson motorsport, hack engineering also.

Yeah driveshafts do seem overkill TBH, I think they say consider it to be fair, but for the best part of a grand, think I'll skip for now!

I know James well at Redish, I have no issues using them generally speaking though it really does depend on the service you want / expect. I do think they've got a bit expensive based on their reputation but then you could say that about a lot of specialists that started small and expanded.

I suspect Darragh at Everything M3's is in the same boat, I caught him when he was in the one man band phase working out the back of his house and you know you could turn up and he would be very reasonable with pricing and you'd get to have a laugh with him. I got some very reasonably priced work done which should have cost a lot more. He's almost a celebrity these days in the M world, Chris Harris and all sorts turn up at his garage so those days are long gone.

I'd say give them a try again, though I don't think they do much that any other competent specialist couldn't do. I wouldn't bother them with Insp 1 / 2 and that kinda stuff anymore. Almost BMW prices.

If you can get the diff out at a local garage as that bit is only heavy and a finger/hand trap you could send it up to JC Racing up North in Darlington he does quite a few and does them for other BMW specialists as well as race teams

Yup think this will be the best option. JC seem good but I'll probably give Dave a go first as he's a bit closer to me and can probably drop it off myself and save on postage.

There is always Mr Vanos

No thanks!

[GT Spec]

So I've just managed to bag a 4.1 gear set after deciding it'll be my 'big' mod for this year, been tempted for a while but saw the gear set on Ebay for £695 from BMW so decided time to bite!
(Well worth keeping an eye on Parks Motor Group, part number: 23008437087 if anyone ever fancies it, by far cheapest I've seen it sold new, seems to come up now and again for sale).

In terms of fitting, anyone got any particular recommendations for places to have it done as well as what else to replace at the same time?
I'm in Wiltshire so good choice of specialists, Redish and Everything M3's being the obvious choice having used them both before. Anyone else worth considering as I suspect they both have long waiting lists for work as usual.

Anything else worth replacing while the job is being done? Car's on 105k miles. Redish recommend driveshafts but this seems a bit overkill to me?

Much as the Redish 'rebuild' option sounds good, not sure I want to pay 2k when I don't think I've got any particular issues with it currently.
Yeah so any advice appreciated!

Darragh at EverythingM in Banbury

I supplied him the crown gear and pinion as you are planning and waited about until the job was completed. Thoroughly recommended!

[Vanne]

As Bee mentioned , changing driveshafts is just sheer stupidity, unless there was something seriously out of whak before that? No shop would recommend that, possibly you miss understood and they mentioned Guibo or the driveshaft carrier bearing?

If you heard correctly, id be deleting that shop from any of my business forth worth.

[AndyBeech]

As Bee mentioned , changing driveshafts is just sheer stupidity, unless there was something seriously out of whak before that? No shop would recommend that, possibly you miss understood and they mentioned Guibo or the driveshaft carrier bearing?

If you heard correctly, id be deleting that shop from any of my business forth worth.

It's on their website to be fair, not spoken to them yet:

We also advise that you consider replacing your Driveshafts (if yours are still original)" (context: Is there anything else you recommend changing at the same time?)

Why would I want complete new Driveshafts?
If original, an E46 M3's Driveshafts (and drivetrain) can be 15-20 years old now.
We find multiple E46 M3's with excessive CV Joint 'play' every week.
Excessive 'play' can be from a mixture of worn CV Joints and/or worn splined ends.
BMW do not, and never will, sell the Outer CV Joints as they are under licence with GKN.
Excessive 'play' contributes to driveline slop and the notorious 'M Clunk'.
Corrosion builds up on the shaft and CV Joints causing an unsightly look for OEM/restorations.
Corrosion commonly grows underneath the ABS Ring and expands it until it hits the sensor.
CV Joint grease commonly breaks down into an oil consistency which further wears the CVJ's.
CV Joint Case Caps commonly leak grease/oil which sprays around causing an unsightly mess.

To be fair, they do specialise in kind of nut and bolt type restorations as well so it's probably more geared towards that kind of customer.

Anyway, I won't be doing driveshafts at the mo, sure they're fine.

[Vanne]

Replacing the DS, would be on my list to do after many many many other things first. I stand by what I said. Advising someone to get a new driveshaft when there are no inherent issues is just plain stupid, and a complete waste of money. If you've got shaft issues, I'd be replacing the guibo and carrier bearing, failing that, I'd be looking at getting my old one rebalanced/refurbed. If you are into wasting cash, I am sure you can find better places in your car to waste that on than in the no issue driveshaft.

I hear your not doing it, and that's good, but your an informed and rather well versed customer.. I wonder how many non knowing customers they've taken for a ride with that..

[AndyBeech]

Out of interest, has anyone replaced the propshaft CV joint while the diff's out? Part 17 on the diagram (26117841003):



Only thinking as like any CV joints it'll wear eventually but at £260 odd, lot of money if it's not common to replace.

[lucasxdiniz]

Out of interest, has anyone replaced the propshaft CV joint while the diff's out? Part 17 on the diagram (26117841003):



Only thinking as like any CV joints it'll wear eventually but at £260 odd, lot of money if it's not common to replace.

I only removed some of the old grease and repacked new lithium grease in there. My car is close to 100k now. There's zero noise from the drivetrain even though by hand I could feel some play in the CV (if normal or not, I don't know).