The 4 speed conversion cross member secret. - PeachParts Mercedes-Benz Forum

winmutt · #1 06-01-2008, 11:18 AM

The 240d auto crossmember is the right size. The drive shaft however is not

. I spent the day comparing to 116 and 115 and none were the correct size.

Cervan · #2 06-01-2008, 03:54 PM

Quote:

Originally Posted by winmutt

The 240d auto crossmember is the right size. The drive shaft however is not

. I spent the day comparing to 116 and 115 and none were the correct size.

None will be the correct size, you must cut your original driveshaft and have it balanced, (Assuming your doing the 617 4 speed swap)

#3 06-01-2008, 09:04 PM

If my 5-speed works out I'll have a euro 4-speed driveshaft to sell. It will be a few weeks before that happens though.

winmutt · #4 06-01-2008, 10:30 PM

Quote:

Originally Posted by Cervan

None will be the correct size, you must cut your original driveshaft and have it balanced, (Assuming your doing the 617 4 speed swap)

I am not certain of that. Legend has it that SOME 116's had them as well. I think perhaps the ones with manual trans? (I should have pulled it when I had access to one).

bgkast · #5 06-02-2008, 11:04 AM

If MB was smart (and they seem to be) they would have designed things so that an automatic was "1 cyl" longer than the manual. I'm supprised the 240D shaft was not correct. What was the problem with it?

Edit: now it makes sense.

winmutt · #6 06-02-2008, 11:58 AM

I am not 100% sure it wouldn't fit. The cross member and carrier bearing were at different positions. I had to measure with a string so take that for what it is worth. Probably worth a try.

vstech · #7 06-02-2008, 02:14 PM

Quote:

Originally Posted by bgkast

If MB was smart (and they seem to be) they would have designed things so that an automatic was "1 cyl" longer than the automatic. I'm supprised the 240D shaft was not correct. What was the problem with it?

... Care to clarify this... I ASSUME you mean longer than the manual...

bgkast · #8 06-03-2008, 01:03 AM

Does it matter which transmission mount is used? My '79 shows an early and late type of mount, the later one has a oval hole in the middle, and the early one (which my car is using) has a round hole that a bolt passes through the middle like so: Cross member->hole in mount->cross member. The mount is also attached at the bottom via two bolts. The auto mount I just got is not shaped to accept the middle bolt so I assume it does not matter.

t walgamuth · #9 06-03-2008, 07:32 AM

Quote:

Originally Posted by bgkast

Does it matter which transmission mount is used? My '79 shows an early and late type of mount, the later one has a oval hole in the middle, and the early one (which my car is using) has a round hole that a bolt passes through the middle like so: Cross member->hole in mount->cross member. The mount is also attached at the bottom via two bolts. The auto mount I just got is not shaped to accept the middle bolt so I assume it does not matter.

I'm not sure what is what from your description, but the bottom line is to use a stick rear tranny mount and make sure your ds is really straight with no abrupt kinks in it.

Tom W

winmutt · #10 06-03-2008, 08:02 AM

Quote:

Originally Posted by t walgamuth

I'm not sure what is what from your description, but the bottom line is to use a stick rear tranny mount and make sure your ds is really straight with no abrupt kinks in it.

Tom W

Use the HD auto tranny mount.

As far as the DS being straight, the "correct" cross member is not centered. It may be centered in relation to the engine -> rear diff but it is off centered on the plate itself.

#11 06-03-2008, 08:25 AM

Are all the different mount models the same height?

t walgamuth · #12 06-03-2008, 09:01 AM

I think the automatic tranny mount is quite a bit taller than the stick mount. So you have to be careful what you use.

Tom W

winmutt · #13 06-03-2008, 09:59 AM

Hrm I seem to remember them all being the same or relatively so. I had all three on hand at one point. I know I currently use the heavy duty auto mount and have no problems. I tore through the 240 and 200 mounts.

#14 06-03-2008, 10:03 AM

My 240D mount is still doing fine.

bgkast · #15 06-03-2008, 10:59 AM

My 240D mount is fine too, but I did not replace it when I did the swap so I would like to now.

Here you can see the early manual mount with the round hole, and the later one with the oval hole. The auto mount seems to be the same as the oval hole manual mount, so that is what I will try I guess. Where did you find a heavy duty mount Winmutt?