E36 328i Automatic - Rear Main Seal

[cleanish_e46 207]

I need to replace the rear main seal on my 1995 E36. What else should I be doing at the same time? Thanks in advance for any advice, Josh

Edited August 27, 2023 by cleanish_e46

[Vass 832]

Manual swap 😏

 

But seriously, transmission mounts, CSB, driveshaft guibo. If you're emotionally attached to the auto box, drop the pan, chuck on a fresh filter & oil. 

[jom 98]

If You're doing the autobox, make sure that you drain the torque converter too. I'd advise using synthetic trans fluid.

[cleanish_e46 207]

2 hours ago, Vass said:

Manual swap 😏

 

But seriously, transmission mounts, CSB, driveshaft guibo. If you're emotionally attached to the auto box, drop the pan, chuck on a fresh filter & oil. 

I’m going to the UK in October / November to visit my parents, hopefully a ZF 320Z in a shed that can come back as carry on. 

I’ve had the car for a week and can confirm, I am not emotionally attached to the auto box, but I will probably do this anyway because, OCD. 

 

[cleanish_e46 207]

2 hours ago, jom said:

If You're doing the autobox, make sure that you drain the torque converter too. I'd advise using synthetic trans fluid.

Appreciate the advice Jo.

[cleanish_e46 207]

This is a list for me, but may help others:

1. Manual Swap 😏
2. Rear Crankshaft Seal - 11142249533
3. Gasket - 11141432240
4. Transmission Mounts - 22316799331 (or Polyurethane Upgrade? (80A))
5. Drive Shaft Support Bearing - 26121225071
6. Drive Shaft Giubo - 26117511454
7. Gearbox Input Shaft Seal - 24121218853
8. Gearbox Output Shaft Seal - 24137509504
9. Automatic Transmission Oil Pan Gasket - 24111219126 ✅
10. Automatic Transmission Drain Plug Gasket - 24111219126 ✅
11. Automatic Transmission Fluid (Synthetic) ✅
12. Automatic Transmission Filter - 24111218899 ✅
13. Selector Shaft Seal - 23128677736
14. Locking Nuts for Flex Disc - 26127536563
15. Exhaust Gasket - 18301716888
16. M8 Copper Nut - 18307620549

RealOEM.com part numbers for my car: 3' E36 BMW 328i. Type Code: BK82

If anyone has anything to add, reply to this topic and I will update the list. Josh

 

Edited October 8, 2023 by cleanish_e46
Updating information that others may also find useful.

[jom 98]

You won't need a guibo if it's an auto box. I spent ages looking for mine....

[cleanish_e46 207]

5 minutes ago, jom said:

You won't need a guibo if it's an auto box. I spent ages looking for mine....

Saving money already Jo! Thanks

[Eagle 1662]

Only negatives using poly transmission mounts for the average car.

May as well inspect and lube to starter motor if its unknown condition

Exhaust gasket for the manifold downpipes and new 4x copper nuts

New lock nuts for flex disc depending on where you ordering from 

Gearbox selector shaft seal (the one the usually leaks)

You can do the driveshaft center sleeve bushing if you wanted , but id probably skip it and just lube it up if in good condition (usually is if the guibo hasn't failed)  

Guibo is easy to source though going by that part number

 

 

[cleanish_e46 207]

1 hour ago, Eagle said:

Only negatives using poly transmission mounts for the average car.

May as well inspect and lube to starter motor if its unknown condition

Exhaust gasket for the manifold downpipes and new 4x copper nuts

New lock nuts for flex disc depending on where you ordering from 

Gearbox selector shaft seal (the one the usually leaks)

You can do the driveshaft center sleeve bushing if you wanted , but id probably skip it and just lube it up if in good condition (usually is if the guibo hasn't failed)  

Guibo is easy to source though going by that part number

 

 

Appreciate the advice Jared.

I was wondering if it was worth using polyurethane mounts with a similar ‘hardness’ to OEM rubber ones, just because polyurethane is a ‘better’ material. 

[Eagle 1662]

The OE mounts generally last a very long time in my experience and rarely truly fail unless they get oil leaking on them. I just replace them because they are very cheap ($10-15ea) and im in the area. Yeah i guess you could say poly is better, but to me i just dont see the need for them and they cost more?

[cleanish_e46 207]

16 hours ago, Eagle said:

The OE mounts generally last a very long time in my experience and rarely truly fail unless they get oil leaking on them. I just replace them because they are very cheap ($10-15ea) and im in the area. Yeah i guess you could say poly is better, but to me i just dont see the need for them and they cost more?

Fair enough, generally my preference is to spend (within reason) on parts and save on labour (doing something twice / more frequently), whether that's my time or someone else's. 

Quote

Exhaust gasket for the manifold downpipes and new 4x copper nuts

Do you need to remove this to get at the rear main seal on these? or are you just recommending it because it's a good time to do it while I'm in there? Thanks 

[Vass 832]

Yeah, the exhaust will have to come off when removing the gearbox, the old gasket will likely be perished and the old nuts will be well rusted. With luck you'll manage to get the nuts off without the studs breaking off. Use plenty of penetrating fluid beforehand.

[cleanish_e46 207]

1 hour ago, Vass said:

Yeah, the exhaust will have to come off when removing the gearbox, the old gasket will likely be perished and the old nuts will be well rusted. With luck you'll manage to get the nuts off without the studs breaking off. Use plenty of penetrating fluid beforehand.

Appreciate the advice Vass. I was without luck when I did it on the E30 so here's hoping!

[Eagle 1662]

Yeah clean end of threads too along with fluid. If they feel like they are binding up when loosening then work them back and forward with more fluid . If still that doesn't work then heat them up with gas torch. No reason for snapping if you aren't forcing them tbh. Wire brush and clean threads then put some anti seize when reinstalling and they will come off easy in the future.

[cleanish_e46 207]

They didn't snap on the E30, but distinctly remember using more heat than I had planned!

[Olaf 3318]

+1 on OEM rubber mounts.  Although they don't fail (unless thrashed), supple rubber absorbs vibrations that your 30-odd year old ones don't.  And they cheap.

[cleanish_e46 207]

10 minutes ago, Olaf said:

+1 on OEM rubber mounts.  Although they don't fail (unless thrashed), supple rubber absorbs vibrations that your 30-odd year old ones don't.  And they cheap.

Appreciate the advice Olaf. It's great to be active in this community again after a break to focus on my health.

On OEM rubber vs Polyurethane, would you say the same for suspension bushings? (Subframe, Trailing Arm, Differential, Front Control Arm...). Keen to hear your opinion too @Eagle and anyone else! 

 

[Olaf 3318]

@cleanish_e46 I'm biased... if it's not a race car, OE spec rubber is all you need - unless you prefer needing to see your urologist or dental sugeon due to persistent jarring.  not to mention the state of our roads these days.

I've had all of the bushes you mention replaced in the first two years with my e30.  it runs Konis & H&R springs.  The whole setup is firm, damped, as you'd expect from a BMW.  I've also done the same on e46 & e60.  Replacing rubber firms things up and restores control, though not to the point my wife or kids complain.  

Most proponents of Poly are under 25 or have replaced completely bagged-out bushings with poly, and are of course impressed and amazed at the improvement.  By the time you've done everything (each part you stiffen reveals shortcomings of the next bagged-out part), it's the hair-shirt solution. Sounds and looks amazing though bloody uncomfortable to wear.  Like I say, if it's a race car, all's great on Poly.

Poly has its application.  Unless you're certain you need that incrrease in stiffness, rubber is relatively inexpensive and far more durable than poly, and is the right compromise for everyday and sporting street use.  BMW test drivers and development engineers logged thousands of hours developing a workable solution for most people, poly does not feature.

[cleanish_e46 207]

"It is a convertible, and it is an automatic, it is not a race car." This is my mantra!

Plan for the car will be something similar to your setup, firm things up after almost thirty years.

[Eagle 1662]

Sealed spherical bushings are better in just about everyway compared to poly usually bar cost. Otherwise it's solid/HD rubber for me. Like @Olafhinted at people go from worn old rubber to poly. New rubber firms things up well enough. If it twists then lube maintenance is required at some point also. Subframe bushings are the probably the only place i mainly used to use poly because it's set and forget and easy to install. I don't like the bright colors most of them use either but that's me

Spherical bushings on trailing arms arms and hub along with and poly or solid subframe mounts make a big difference in rear end control, but can a bit harsh over sharp bumps in road with low profile tyres not helping.

I'd just stick to fresh rubber and enjoy it.

[cleanish_e46 207]

What do you use for subframe bushings now? Agree with you on the colours!

I think I'll inspect how worn things are currently and that'll give me an idea of 'when', but fresh rubber sounds like the go when that time comes. Need to prioritise keeping fluids where they should be, and then I can save for the next job(s).

[Eagle 1662]

Got solid ones in my E46 atm. Before that was meyle HD rubber ones.

Bushing refresh on E36 is pretty cheap parts wise probably $300-400 at a guess. I wouldn't bother inspecting them and just do them all at once when you got the funds. Add struts/shocks, links and mounts if not already done and then you good

[cleanish_e46 207]

Turns out the previous owners mechanic had misdiagnosed where the oil was leaking from, and I should know better than to take their word for it but struggling to get under there myself at the moment unfortunately! 
 

Took the car to Sam at @HELLBM, who I can’t recommend enough. Transmission got a bit of a birthday since we’d already ordered the parts, and no more oil leak. 
 

Chalk it up as a win.