Need Help - Tranny Swap to Manual - PeachParts Mercedes-Benz Forum

TomJ · #1 10-02-2003, 04:53 PM

Seems that I either have the ONE car in the world with a non-standard crank, or the "simple" swap of a 240D manual into a 300D is BS.

Just found out the hard way that the pilot bearings for the 240D are 35mm OD and the crank hole ID on the 300D is 34mm. Hardly a doable press fit (0.040).

So..., all the work I've put into procuring a tranny, building it, rebuilding the shift linkage, etc. was all for 'naught.

Unless..., Mercedes has a non-standard OEM pilot bearing that is 34x15x8 (but that's probably NOT the case and I'm hosed!)

So..., anyone remember what the bearing dims were of the pilot bearing when you did a swap to a manual?

Anyone out there who has ACTUALLY done this? Themselves???

HELP!!!!!

R Leo · #2 10-02-2003, 05:27 PM

Worldpac shows the following three different pilot bearings for the various iterations of the 1980 240D manual that I plan to use in my conversion (to be done later this fall).

I1010-35528
I1010-23307
I1010-22951

Maybe these are because they are different ODs?

Since bearings are all (I believe) manufactured in metric dimensions, you should be able to go to a bearing supply house and spec a sealed ball bearing with a shaft diameter that is the same as the pilot shaft on your tranny and the outer race with the ID measurement from your crank. It might even be cheaper than the MBZ part.

You might also call the folks that sponsor this site...lots of technical knowledge there.

I don't have a measurement for my original pilot bearing since I was unable to remove the pilot bearing from the donor vehicle because it was as a really tight fit.

leathermang · #3 10-02-2003, 05:47 PM

Make sure you know what size diameter you need and get a $8 reamer and run it in there while spraying some pb- blaster at the same time... push it in and bring it out while turning the same direction.. IE... you never turn a reamer backwards...
This is if some combo of actual correct parts are not available...

TomJ · #4 10-02-2003, 08:53 PM

Bearings ARE metric and 35x15x11 is a std size, but NOT 34mm OD. Non exist. This is from bearing houses coast to coast.

Also, we've gone through all the bearings that merc lists and NONE are 34mm OD.

The reamer ID is intriguing. I have many machine size reamers, but none that large. Something that's 34mm is going to be MUCH more than $8, but it's still a viable option (if I can find a bottom reamer for the shallow crank relief?)

TomJ · #5 10-02-2003, 10:13 PM

Well, after considering reaming the crank while in the car and what it would take to do so on a forged steel shallow bore, I've decided, that's NOT an option!

Here's what I've come up with so far, please give an educated critique.

Bought a bearing that is 32mmx15mmx9mm and took some brass bar stock and made a bearing shim out of it.

Here's the smaller ID bearing (2mm smaller OD than what I need) next to a 35mm (that is 1mm too large):

Here's the bar stock:

Machining the ID for a press fit over the small OD bearing:

I made the "shim" a "pocket'" so the sleeve wouldn't slide off when it is pressed into the crank with the bearing it it. It is also deeper than the bearing as I wanted as much "bearing" surface in the hole as I could get.

Here's the finished product with the smaller bearing pressed into the brass sleeve that is machined to an OD of 34mm (with 1/2k press fit):

Now whether or not it'll last is another question. The brass should have a thermal expansion rate about three times that of forged steel so at working temps, there shouldn't be a problem with it staying put and I'm sure it will relieve axially as the bearing race and the forged crank aren't going to give way to the brass.

Question is, will it spin when the engine is cold (and after a few thermal cyclings have "re-sized" it) and destroy itself?

Am thinking of making one out of mild steel to more closely match the thermal expansion characteristics of the crank and bearing, but don't have any bar stock right now.

R Leo · #6 10-02-2003, 10:43 PM

That bushing/bearing shim really should work just fine. All you need to do is support the end of the pilot shaft and it looks like that's what you accomplished. The only time there's a speed difference between the pilot shaft and the crank is when the clutch is disengaged...not much opportunity for wear.

In fact, you could probably dispense entirely with the bearing and machine a pilot bushing out of oillite/sintered bronze. Older American cars used pilot bushings from the git-go (dunno what they're doing these days).

Many moons ago, I had a 1954 Chevy truck that had a 283/3 spd stuffed into it. It had been run sooo long without a pilot bearing, the end of the crank had been beaten into a cone-shaped hole by the pilot shafts of countless transmissions.

I guess because the front end of the pilot shaft wasn't supported, The damned thing wouldn't stay in 2nd gear so I found a new bushing, wrapped about four layers of brass shimstock around it and beat it into the crank with a mallet.

Worked fine from there on for the remaining 4-5 years I had the truck.

But, this whole exercise has me troubled because I've been under the impression that these MBZ auto to manual swaps were pretty much a painless deal.

Can you give us a provenance of the various parts involved in this tranny swap? ie: year of transmission, year of the engine, any known history...etc.

leathermang · #7 10-02-2003, 11:08 PM

Randy,,, this is not a new problem... this has been discussed before.
I think you have done a beautiful job and taken beautiful pictures of it...
I think you did well to stick with the bearing instead of reverting to a bushing.... oilite is not easy to properly machine.. in fact I don't think they suggest it at all... I think it mashes the pores you need to transmit oil together where they don't work right...
One other possibility, since you have the equipment...is to mount that one mm too large bearing in a holder and grind the outside down to the proper size....

LOL.. it seems to me that you have the equipment to MAKE a reamer of the proper size and type also....

diesel don · #8 10-02-2003, 11:56 PM

You're way beyond my expertise. I guess I was fortunate because about a month ago, I ordered a pilot bearing while mating a 300DT with a 4 speed manual. It pressed in very nicely.

Don

leathermang · #9 10-03-2003, 12:01 AM

OK DON... don't just tease us..... where did you get it ?
I am under the impression that all sizes of bearings are available SOMEWHERE.... they just could not find it....

TomJ · #10 10-03-2003, 12:16 AM

Quote:

... Can you give us a provenance of the various parts involved in this tranny swap? ie: year of transmission, year of the engine, any known history...etc.

Here's the skinny so far;

Pulled a junkyard tranny from a 1982 240D along with the following parts; shifter assy (complete), shift linkages, flywheel, throw-out lever, front half of driveline, all the bolts to the flywheel AND pressure plate (and of course to the linkage assy.)

Vehicle it's (maybe) going into is a 1984 300D Turbo Diesel.

The shifter assy was completely dis-assembled and rebuilt while waiting for a new clutch and pressure plate. I'll post pics of that in a new thread soon.

Completely de-greased the tranny and replaced the in/out bearings in the tranny, the front and rear seals, all shifter seals (funky silvery O-rings from MB) and the shifter bushings.

A buddy in the local full-size Jeep club has done this swap to four vehicles and says the driveline needs to be cut-down two inches.

I called six different driveline places and the response ranges from "can't do it to those type driveshafts" to "it'll cost $150 and we need the other driveline to balance as a complete assembly.

What I've learned so far;

1) driveline could be a major headache to get modified.

2) pull your bad automatic ASAP and take an inside mic to the crank bore to see if you'll have the problem I'm having with the pilot bearing. If it mic's 34mm, part the car out on ebay and find another. If it's 35mm, you're good to go.

3) don't think about going to this much work if your NOT going to use a new throw-out..., excuse me, "release" bearing, pressure plate and clutch.

4) their's lot's more to D/C than I originally thought when pulling the auto trans. Wires, cables, fittings, cooler lines, etc.

5) somehow, find caps for the radiator coolant line connections (not a "plug", you need a "cap")

6) seems to be no way to remove the shift console without breaking the plastic retainer that holds it at the back so find one at a junkyard that "might" not be broken.

7) might as well dis-assemble all of the switches in the shift console while it's out for the shifter swap. Easy to get to now and they are cake to take apart and re-new (will post on that with pics later too).

8) remember to make a note of the last 6 digits (or all for that matter) of the VIN of the DONOR vehicle for future ref.

9) make a note of the transmission # cast into the side at the horizontal parting line (you'll need this when buying the various tranny parts)

10) for G**'s sake..., get someone ELSE to do the work (unless your're professionally un-employed like me ;-)!!!)

Advice: since the car is up on jacks all four corners at this point, might as well change the diff fluid (to synth).

While under there, you'll notice "Gee the axle boots are shot, no more lube in the CV's and they're rusted in there?"

Replace the axle seal at the differential when you take the axle out for any reason (but it's NOT an inner axle seal it's a "Differential Side Cover Seal". Go figure.)

Replace the oil pan gasket too since it'll be sitting for a while in the air while waiting for the right parts to come.

As soon as it's up on jacks, take some engine cleaner to the complete underside, engine and tranny and spray it off good. Getting black and greasy for days on end can strain a relationship (or be a major vector for close range gunshot wounds!)

unkl300d · #11 10-03-2003, 01:14 AM

TOMJ, LOOK UP FELLOW MEMBER;

RIDGE

HE HAS DONE THESE PROJECTS

R Leo · #12 10-03-2003, 06:44 AM

TomJ,
Despite what you're hearing, those shafts can be altered. Read my post here about Thrash Driveshaft in San Antonio, TX:
http://www.peachparts.com/shopforum/showthread.php?threadid=75078&highlight=thrash

But, don't alter your driveshaft until you have the tranny bolted up and can take a good measurement of the length that it needs to be. Prior posts have led me to believe that the number is something like 4", not 2"

This is all soooo weird. Ridge and Grimgaunt have both done a butt-load of these swaps and have never once mentioned a pilot bearing problem. In fact, I've done a fairly through search of the diesel forum and cannot find any reference to anything like this.

BTW- I went out and measured the torque converter pilot snout on TO's dead automatic (out of an 85TD) and it is 35mm. I'm keeping my fingers crossed....

IMHO-an oillite bronze bushing is an acceptable fix. A ball bearing up there is another example of Daimler overengineering.

leathermang · #13 10-03-2003, 08:40 AM

In response to an email I got from Randy :

"Beemer Precision, Inc. is the manufacturer of Oilite and Excelite Bearings. Oilite has been a name common in manufacturing for many years. Now Beemer Precision, Inc. has an excellent Web site to fill your needs. We recommend requesting a catalog through the Web site as well. You will find useful tips about machining Oilite on page 7 of the catalog. A helpful Tip from page 7 concerning machining is, "honing and grinding are never recommended on Oilite bearings on any surface which will become a bearing surface". You can find Beemer Precision, Inc. at "www.oilite.com"."

There are differences of opinion on this... but I originally read it on an instruction sheet in a box of oilite bearings.... since it was from the manufacturer I took it as gospel...

diesel don · #14 10-03-2003, 08:40 AM

Leathermang:

You must understand that this was all new to me and by being a rookie, I apparently got lucky with the bearing fit. However, here is as much detail as I can muster:

1. The chassis into which the 300D-t was entering was a 1982 240-D 4 speed. I used that tranny.

2. I ordered the pilot bearing from fastlane I believe (it is possible that it came from performance products but usually I order from phil). I simply ordered the one that was available for that year and make (1982 240D).

3. The engine was from a 1983 300D-t. Therefore, the swap sounds nearly identical (only one year separating the engines).

4. The driveshaft issue might be better suited to find a euro manual off a 300D. I was fortunate enough that have that particular parts car and therefore didn't have to shorten it.

5. My tranny linkages were shortened 4" and they work perfectly.

Don

TomJ · #15 10-03-2003, 09:20 AM

Quote:

Originally posted by R Leo
...........BTW- I went out and measured the torque converter pilot snout on TO's dead automatic (out of an 85TD) and it is 35mm. I'm keeping my fingers crossed....

Yes, so did I when I first found that the bearing wouldn't fit. The snout of the auto trans is indeed 35 mm, so I wen't back to attempting to install the bearing with no luck.

THEN I checked the flexplate (not really "flex", cast iron machined plate for the TC). The hole in the flex plate is 35mm and THAT is what the TC snout pilots into, NOT the crank (the flex plates in these are almost 1" thick!).

That's what really fooled me into thinking that it was like every American vehicle I've worked on with the TC piloting off the end of the crank, but this TC doesn't even reach far enough to TOUCH the crank, so the pilot hole in it is irrelevant. It could go completely without one for that matter.