350SL / SLC 280SE 3.5 clutch - PeachParts Mercedes-Benz Forum

rwd4evr · #1 02-05-2018, 03:42 PM

I'm trying to find a clutch disc or complete kit for my 450slc. It's converted with 350sl/SLC 4 speed parts. No luck finding one with KAWE or LUK part numbers. Does anyone know the Sachs kit part number? Any possibility of a more common clutch will swap? I think I only need a disc since it broke but........

Frank Reiner · #2 02-05-2018, 07:01 PM

rwd:

Consider using a 10-10.5" domestic clutch. Face the flywheel friction surface out to accept the OD of the pressure plate & drill new bolt pattern. A convenient pressure plate is the 1985 and later Mustang 5.0. It is known as the Ford "Metric". Use a Chevy disc; the 1 1/8" - 10 spline fits the MB input.

rwd4evr · #3 02-05-2018, 08:25 PM

So the v8 g76/27 and 6cyl g76/18 use the same 1 1/8x10 splines on the input shaft? If so then wouldn't it make more sense to use a early Chevy 10.4 clutch kit so it's all matching? How about clutch release finger height? I actually have a Chevy Malibu flywheel and clutch in my parents garage I can measure.

Frank Reiner · #4 02-05-2018, 08:42 PM

rwd:

The Chevy package will work fine; the Ford clutch cover OD & bolt pattern are slightly smaller. Both have a 10.4 disc.

rwd4evr · #5 02-05-2018, 08:49 PM

So you don't think it will be any clearance issues with the starter nose or shaft, or bellhousing? And the release height is similar to the Mercedes PP? I have to scope it again but I don't remember there being a whole lot of room to the outside of the Mercedes PP to the ring gear area.

rwd4evr · #6 02-07-2018, 04:57 AM

I've been reasearching a bit more and found that BMW uses the same 1 1/8" 10 spline input and 240mm Clutches. Im curious if they use the same cover bolt pattern? I'm still leaning towards the Chevy clutch for a number of reasons, price being one and availability of higher performance models being another. Plus as I go down the drivetrain breaking things that will get replaced with cheaper stronger domestic v8 related parts they will interchange easier. I still don't get why a Sachs clutch kit for a
85 hp Mercedes 240d is $275 and one for a 350hp big block Chevy truck is $84. Horse****.

rwd4evr · #7 08-05-2018, 01:39 AM

Hey just want to warn anyone looking at messing with the V8 manual cars, 350sl/SLC and the 280se/sel 3.5 and 300se/sel 3.5/4.5. (yes 300sel 4.5 was available with the manual in the US, dont know how many were built though.)
the trans shaft IS NOT the same 1 1/8" shaft as all the rest of the early 4/5/6 cyl gas and diesel engines. iIt is a slightly SMALLER 21x26mm 10 spline shaft. also not the same as a ford 1 1/16" shaft. Crap.

Tony H · #8 08-09-2018, 11:50 PM

Did you ever find out if the Chevy disc fits the trans input shaft or if any commonly available disc fits? I have been wondering if the stock clutch will last with the power/torque of a 5.6L engine. I don't plan on aggressive takeoffs.

rwd4evr · #9 08-10-2018, 05:36 AM

No the chevy disc will not fit. A chevy or bmw clutch disc will fit the 1 1/8" 10 spline 6 cyl trans fine. 'Many BMW 240mm pressure plates will bolt to the benz v8 flywheel too, I can't speak about installed height and those things yet. The v8 3.5 trans is the only car I have found that has ever used this god damn spline. It 21x26 mm 10 spline. The chevy /BMW/ 6cyl benz clutch disc will fit over the v8 shaft but it is loose and would absolutely wreck **** if you tried to use it. The ford 1 1/16" doesn't fit either. So you are stuck with it. That being said I broke mine absolutely beating the snot out of it. The pressure plate never slipped at all. It just had a sprung hub or rivet failure. It going back in the car today with the disc and hub welded and we'll see what happens. I did balance it after welding. It has a welded diff so it's not just spinning one tire. An auto cross and two drift events plus lots of street thrashing. If you drive it like a normal maniac it will be fine I think. I am an exceptional maniac. Like 55mph topped out 2nd gear full throttle clutch kicks to initiate a drift all day long. The trans seems pretty tough. It's very similar to the 6cyl internally and I know a guy that dynoed his turbo m110 powered w114 at 408 wheel HP. through the 6 cyl 185mm diff I'm running too. I believe the small v8 swingaxle cars use a 185 ish ring gear too.

Tony H · #10 08-10-2018, 05:06 PM

Thanks for the info. Maybe a clutch shop could build a custom disc out of the 3.5 disk. You can use a hydraulic throwout bearing to get the adjustability you may need to accommodate different pressure plates and much better action also. So the clutch never slipped? how is the transmission holding up?

rwd4evr · #11 08-11-2018, 04:49 PM

Seems to be ok. Bearing feel smooth. Some input shaft play but different manuals are different with that and I have nothing to go on to compare. It never shifted very well, I think the syncros are bad. Definitely a , clutch , pull a bit and wait for it to agree with shifting. Try to bang shift and its grinding. Hard to say about durability with more power but I doubt 70 or so more hp and probably about the same added torque is gonna put more stress under even spirited driving compared to 6500 rpm clutch dumps with 200ish hp 220 lb ft. Next weekend drifting with the new unsprung itch disc will tell something. Of course your traction and rear ratio play a big part in driveline failure too. A 2.47 gear with traction will blow up a trans way before a 3.69.

rwd4evr · #12 08-11-2018, 06:25 PM

Quote:

Originally Posted by Tony H

Thanks for the info. Maybe a clutch shop could build a custom disc out of the 3.5 disk. You can use a hydraulic throwout bearing to get the adjustability you may need to accommodate different pressure plates and much better action also. So the clutch never slipped?

No I've never had any noticeable slipping, when I dump the clutch it's instant smoke show. I found a guy that will build a solid hub ceramic puck clutch disc with my splined hub center. I'm pretty sure I'll be moving away from this trans in the near future though. I have an easy iron block t5 adaption with a removable auto bell and plate and I rally am trying to go alloy manual trans so I can just throw the 5.6 in it. I have a beat alloy trans I'm gonna open up and measure to see if it's worth cutting it apart for the bell. T5 and hydro throw out ,modified BMW or ford flywheel.

David Hendy · #13 08-12-2018, 09:02 AM

I had to source one of these SL 3.5 clutch discs for a customer several months ago.

This is the one that I bought. It was identical the used clutch he had...

https://www.ebay.com/itm/Mercedes-Benz-280SE-C-300SEL-NOS-Sachs-Clutch-Disc/352418517754?epid=26014286920&hash=item520dc7d2fa%3Ag%3Auz4AAMXQHDlRcoao&_sacat=0&_nkw=mercedes+NOS+clutch+disc&_from=R40&rt=nc&_trksid=p2057872.m570.l1313.TR9.TRC1.A0.H0.Xmercedes+NOS+clutch+disc.TRS0