Is there a 328i diff cover with cooling fins?

Biginboca · 05-17-2018, 09:32 AM

Anyone know of a way to add some cooling to our rear diffs?

Phyrexia · 05-17-2018, 02:41 PM

If you move up to the big diff, VAC makes/made a cover for the 215mm diffs. But I believe this would entail a full 335 rear subframe swap - I'm not sure.

Do you suspect it's overheating? I've seen a pump and external oil cooler setup before but it seems like heavy overkill unless you're tracking. (When are you gonna turn this car into a full race car, anyway?

)

Biginboca · 05-17-2018, 03:35 PM

Quote:

Originally Posted by Phyrexia

If you move up to the big diff, VAC makes/made a cover for the 215mm diffs. But I believe this would entail a full 335 rear subframe swap - I'm not sure.

Do you suspect it's overheating? I've seen a pump and external oil cooler setup before but it seems like heavy overkill unless you're tracking. (When are you gonna turn this car into a full race car, anyway?

)

I’m not really thinking I need more cooling it’s just a DD and occasional Autocross car. But since I’m doing another diff swap and putting in the lsd I figured why not address it now if possible.

The LSD generates traction through friction so it seems like some added cooling wouldn’t be a bad idea...

Eagle1oh7 · 05-17-2018, 06:39 PM

I know that there is because some of the guys here have one, but I don't think you need a 335i subframe swap, aren't they the same part anyways??

Biginboca · 05-17-2018, 07:06 PM

Quote:

Originally Posted by Eagle1oh7

I know that there is because some of the guys here have one, but I don't think you need a 335i subframe swap, aren't they the same part anyways??

Apparently there is one that fits. And BudVlad probaly has the answer as to which one it is...

http://www.e90post.com/forums/showth...1079016&page=2

My question now is, are there any cover differences in the 328i differentials, meaning 328i and 328xi because the diff I’m building is from a 328xi (for the 3.91 ratio)...

Biginboca · 05-17-2018, 07:23 PM

So according to real oem the 328i and 328xi both use the 188L cover and I believe the 188k finned cover (p/n 33117516280) fits those diffs.

Hoping BudVlad can confirm that since it seems he’s running one of the vented covers...

Phyrexia · 05-17-2018, 07:28 PM

Quote:

Originally Posted by Eagle1oh7

I know that there is because some of the guys here have one, but I don't think you need a 335i subframe swap, aren't they the same part anyways??

I think I was thinking of the M3 rear subframe.

Biginboca · 05-17-2018, 08:50 PM

While I’m at it I just want to drop this picture from that other thread in here. This is the vented cover that fits on a diff from a 128i/328i....

BudVlad · 05-18-2018, 01:26 AM

P.No. 33117516280 will fit 328i diff.

Biginboca · 05-18-2018, 04:56 AM

Quote:

Originally Posted by BudVlad

P.No. 33117516280 will fit 328i diff.

Did you have any issues mounting it into the car? In the other threads I saw some references to using a 15mm spacer and different mounting bolt but it might have been on another model, not the e90/92.

BudVlad · 05-18-2018, 05:27 AM

No problem with mounting. I used all original mounting bolts. The only issue is exhaust pipe touching one rib as you can see on the other picture. I cut that rib off.

Biginboca · 05-18-2018, 05:35 AM

Quote:

Originally Posted by BudVlad

No problem with mounting. I used all original mounting bolts. The only issue is exhaust pipe touching one rib as you can see on the other picture. I cut that rib off.

Ok great info, thank you sir! Cover is ordered...

atmosphericM · 05-18-2018, 10:33 AM

Yup a fin just needs to be trimmed otherwise it works.

Biginboca · 06-09-2018, 06:15 AM

Ok just wanted to update this thread in case anyone finds it searching in the future. The cover Part Number 33117516280 as stated above is a direct bolt up to the diff as stated.

There are a couple issues that need to be addressed to mount the diff into the car besides the trimming of the last fin on the left to clear the exhaust.

The cover’s chassis mounting point at the rear is not the same height as the original cover. There is a 15-16mm difference so although you can mount the cover on the diff perfectly fine, you can’t just bolt it up into subframe of the car. BMW makes 5mm thick aluminum shims and you can use 3 of them. Here is the part number:

BMW Spacer Ring (5mm) - 33176779816

When I looked 3 of these aluminum Spacers/Shims weren’t available in US and they were back ordered from Germany. So a trip to fastenal landed me some stainless washers I stacked to use instead.

Also obviously the single original bolt that mounts the rear of the diff to the subframe is only 110mm long and will now be too short to use with the 15mm spacer that you need to make. I found BMW makes a bolt that’s exactly 15mm longer (125mm) part number:

BMW Hex Collar Screw (M14x1.5x125-10) - 33177852488

Finally some people mentioned 3 of the 8 bolts that mount the cover to the diff need to be longer. So I ordered 3 longer bolts with the cover and then found my stock cover was already being held on with 5 short bolts and 3 longer bolts. So it was a waste to order those because my diff already had 3 longer bolts lol

Biginboca · 06-09-2018, 07:35 PM

So the job is done. For the record here’s how I trimmed the last fin:

Diff installed perfectly with the shims and longer bolt. That cover trim was perfect to clear my exhaust, that section where it would have hit is factory pipe so if you have the factory exhaust at that point the trim I show above is good.

I know there are many LSD’s, but this is mine and it’s a 3.91...

upload a gif

Radu328i · 04-24-2019, 02:43 AM

Is is there a chance to replace the diff cover with the pumpkin bolted on the frame or it is necessary to remove the diff from the chassis? Thanks.

Biginboca · 04-24-2019, 04:12 AM

Quote:

Originally Posted by Radu328i

Is is there a chance to replace the diff cover with the pumpkin bolted on the frame or it is necessary to remove the diff from the chassis? Thanks.

You need to drop the diff from the chassis. It’s really not that hard and I can’t foresee any way to replace the cover otherwise.

Radu328i · 04-24-2019, 10:27 AM

Thank for your answer. I want to change the diff oil but I was not sure to buy right now or later the diff fined cover.

05-17-2018, 09:32 AM	#1
Biginboca Colonel 3791 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	Is there a 328i diff cover with cooling fins? Anyone know of a way to add some cooling to our rear diffs?
	Appreciate 0 Tweet Quote

05-17-2018, 02:41 PM	#2
Phyrexia Resident Pedant 509 Rep 794 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	If you move up to the big diff, VAC makes/made a cover for the 215mm diffs. But I believe this would entail a full 335 rear subframe swap - I'm not sure. Do you suspect it's overheating? I've seen a pump and external oil cooler setup before but it seems like heavy overkill unless you're tracking. (When are you gonna turn this car into a full race car, anyway? ) __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+
	Appreciate 0 Quote

05-17-2018, 06:39 PM	#4
Eagle1oh7 Lieutenant Colonel 291 Rep 1,710 Posts Drives: '11 328i Sedan Join Date: Oct 2012 Location: Chula Vista CA iTrader: (0)	I know that there is because some of the guys here have one, but I don't think you need a 335i subframe swap, aren't they the same part anyways?? __________________ DONE: Seibon CF Hood, M3 Rep, MSport rear w/DD CF Diffuser, M3 Rep Skirts, Seibon CSL trunklid, Forgestar F14 18s w/Michelin PSS, Eisenmann catback, AA Headers, BPC Stage 2, Charcoal Delete+revMotor+AFE Drop In filter FUTURE MODS: LED headlights, CF rooftop, M3 Suspension Conversion, Dinan CAI Mod
	Appreciate 0 Quote

05-17-2018, 07:23 PM	#6
Biginboca Colonel 3791 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	So according to real oem the 328i and 328xi both use the 188L cover and I believe the 188k finned cover (p/n 33117516280) fits those diffs. Hoping BudVlad can confirm that since it seems he’s running one of the vented covers...
	Appreciate 0 Quote

05-17-2018, 08:50 PM	#8
Biginboca Colonel 3791 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	While I’m at it I just want to drop this picture from that other thread in here. This is the vented cover that fits on a diff from a 128i/328i....
	Appreciate 0 Quote

05-18-2018, 01:26 AM	#9
BudVlad Old Geezer 380 Rep 1,193 Posts Drives: 08 E92 N53B30 Join Date: Jul 2007 Location: Budweis iTrader: (0) Garage List 2008 E92 N53B30 [10.00]	P.No. 33117516280 will fit 328i diff. Attached Images __________________ Last edited by BudVlad; 05-18-2018 at 01:32 AM..
	Appreciate 3 Biginboca3790.50 Eagle1oh7290.50 lab_rat396.50 Quote

05-18-2018, 05:27 AM	#11
BudVlad Old Geezer 380 Rep 1,193 Posts Drives: 08 E92 N53B30 Join Date: Jul 2007 Location: Budweis iTrader: (0) Garage List 2008 E92 N53B30 [10.00]	No problem with mounting. I used all original mounting bolts. The only issue is exhaust pipe touching one rib as you can see on the other picture. I cut that rib off. __________________
	Appreciate 1 Biginboca3790.50 Quote

05-18-2018, 10:33 AM	#13
atmosphericM Basic Bimmer 523 Rep 930 Posts Drives: E92 328i 6MT ///M Join Date: Sep 2017 Location: B'ham iTrader: (1) Garage List 2013 BMW 328i Coupé ... [10.00]	Yup a fin just needs to be trimmed otherwise it works.
	Appreciate 1 Biginboca3790.50 Quote

06-09-2018, 06:15 AM	#14
Biginboca Colonel 3791 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	Ok just wanted to update this thread in case anyone finds it searching in the future. The cover Part Number 33117516280 as stated above is a direct bolt up to the diff as stated. There are a couple issues that need to be addressed to mount the diff into the car besides the trimming of the last fin on the left to clear the exhaust. The cover’s chassis mounting point at the rear is not the same height as the original cover. There is a 15-16mm difference so although you can mount the cover on the diff perfectly fine, you can’t just bolt it up into subframe of the car. BMW makes 5mm thick aluminum shims and you can use 3 of them. Here is the part number: BMW Spacer Ring (5mm) - 33176779816 When I looked 3 of these aluminum Spacers/Shims weren’t available in US and they were back ordered from Germany. So a trip to fastenal landed me some stainless washers I stacked to use instead. Also obviously the single original bolt that mounts the rear of the diff to the subframe is only 110mm long and will now be too short to use with the 15mm spacer that you need to make. I found BMW makes a bolt that’s exactly 15mm longer (125mm) part number: BMW Hex Collar Screw (M14x1.5x125-10) - 33177852488 Finally some people mentioned 3 of the 8 bolts that mount the cover to the diff need to be longer. So I ordered 3 longer bolts with the cover and then found my stock cover was already being held on with 5 short bolts and 3 longer bolts. So it was a waste to order those because my diff already had 3 longer bolts lol Last edited by Biginboca; 06-09-2018 at 06:41 AM..
	Appreciate 3 atmosphericM522.50 spidertri478.50 lab_rat396.50 Quote

06-09-2018, 07:35 PM	#15
Biginboca Colonel 3791 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	So the job is done. For the record here’s how I trimmed the last fin: Diff installed perfectly with the shims and longer bolt. That cover trim was perfect to clear my exhaust, that section where it would have hit is factory pipe so if you have the factory exhaust at that point the trim I show above is good. I know there are many LSD’s, but this is mine and it’s a 3.91... upload a gif
	Appreciate 4 BudVlad380.00 atmosphericM522.50 tetsuo1111245.50 lab_rat396.50 Quote

04-24-2019, 02:43 AM	#16
Radu328i Enlisted Member 23 Rep 32 Posts Drives: BMW 328i N52B30 Join Date: Mar 2017 Location: Romania iTrader: (0)	Is is there a chance to replace the diff cover with the pumpkin bolted on the frame or it is necessary to remove the diff from the chassis? Thanks.
	Appreciate 0 Quote

04-24-2019, 10:27 AM	#18
Radu328i Enlisted Member 23 Rep 32 Posts Drives: BMW 328i N52B30 Join Date: Mar 2017 Location: Romania iTrader: (0)	Thank for your answer. I want to change the diff oil but I was not sure to buy right now or later the diff fined cover.
	Appreciate 0 Quote