Pilot Bearing A Tight Fit, Possibly A 85 crank? - PeachParts Mercedes-Benz Forum

charmalu · #1 10-17-2013, 09:39 PM

Back in April I found a 1980 300SD in PNP that was hit in the left rear, and about shoved the bumper all the way to the rear window. tweeked the body where the Drivers door is in a bind opening/closing.'

Car looked to have been always garaged, good crack free leather seats, crack free dash, good looking wood etc....

Looking under the hood was a totally rebuilt engine and transmission. Rebuilt IP, Injectors, Vac Pump, Starter, water Pump etc, etc....WOW!!!! it`s mine.

Everything Fan to FW out the door was $468.

The 80 SD used a 617.950 engine, (110HP) and first yr for the EGR, I noticed it has the pre EGR Manifolds, so looked at the eng number on the side of the block, and they up graded to a 617.951 as used in the 81 - 85 300SD, ( 123HP)

Looking at the Air Filter they wrote in a date and mileage, and comparing it to the speedometer, they went 1187miles before the accident.

OK now lets fast forward to today.

Installing the Pilot Bearing, it was difficult getting it in, I mean it was a tight fit, not like the one I installed in another 617 engine which went in very easy. I had to drive it in to seat it. used a Socket to drive it in against the outer ring of the bearing.

Installed the clutch Disk and Pressure Plate, then trying to get the 4-spd box on, it will not go on. It goes on to about 2" from the adaptor plate. Just will not go on no matter how much I wiggle it, push it and talk to it.

Now Iam thinking that when this engine was gone through, maybe they got one from an 85 that has the smaller Crank hole. Up to 84 the crank hole is 35mm and the 85 is 34mm.
I notice it has an upper pan from a Federal spected engine as it has the drain tube for the Oil Separator. 85 doesn`t have this.

So when I drove the bearing in the Crank, maybe it squeezed it down to where the Input Shaft of the trans won`t slip in or it is slightly tilted. though it does seem to be seated in squarely.

Soooo, if this is the smaller Crank hole, think maybe I`ll see my Machinist friend Dan and have a Bushing made. The SD-22 Diesel engine in my Datsun PU has a bushing and has worked just fine. It just supports the end of the Input Shaft. I didn`t think of measuring the crank Hole before pounding the bearing in. whodathunk it wuda been different?

Dang, now I need to source a Pilot bearing Puller for my Slide hammer, and I had plans of dropping this back into the Engine bay maybe tomorrow.

Charlie

vstech · #2 10-17-2013, 09:58 PM

check the top of the intermediary plate, see if there is a hole for the tach pickup... if so, it's an 85...
right behind the head...

charmalu · #3 10-17-2013, 10:09 PM

No hole, had the older style plate.

It has the plate with the hole now, as it is going into the 85 300D.

Charlie

vstech · #4 10-17-2013, 10:14 PM

I find it difficult to believe you could hammer a full millimeter difference bearing into the hole...

charmalu · #5 10-17-2013, 10:42 PM

At this point Iam only guessing the possibility of the crank being smaller, and as to why the Trans Snout will not fit into the Bearing.

Iam going to pull the bearing tomorrow soon as I find a bearing Puller. then see if I can measure the crank hole with the FW attached. NO way Iam pulling it off and have to buy another 12 FW bolts.

Looks a little tight getting my micrometer inside the FW to measure, we`ll see how it goes.

Iam not saying it is 34mm, just a guess right now, thinking how difficult it was to get that bearing in, when the other engine it almost fell in, in comparison.

Well it is just a silly little millimeter.

Charlie

charmalu · #6 10-17-2013, 10:53 PM

Some info I dug up on the subject of the 34 vs 35mm crank hole, for anyone reading about this for the first time.

http://www.peachparts.com/shopforum/diesel-discussion/197064-pilot-bearing-4-sp-swap.html

This thread is where TOMJ made a bushing for the Crank.

http://www.peachparts.com/shopforum/diesel-discussion/76297-need-help-tranny-swap-manual.html

This Post he had the bearing spin after 8 months. Pictures are gone.

http://www.peachparts.com/shopforum/1759866-post1.html

Charlie

whunter · #7 10-17-2013, 11:37 PM

Quote:

Originally Posted by charmalu

At this point Iam only guessing the possibility of the crank being smaller, and as to why the Trans Snout will not fit into the Bearing.

Iam going to pull the bearing tomorrow soon as I find a bearing Puller. then see if I can measure the crank hole with the FW attached. NO way Iam pulling it off and have to buy another 12 FW bolts.

Looks a little tight getting my micrometer inside the FW to measure, we`ll see how it goes.

Iam not saying it is 34mm, just a guess right now, thinking how difficult it was to get that bearing in, when the other engine it almost fell in, in comparison.

Well it is just a silly little millimeter.

Charlie

I just went through this on a 1985 300D.

I gently used a dremel with 180 grit barrel sander, to clean the crankshaft bore.

The transmission pilot shaft:
#1. Buy a pack of 180 grit sandpaper Body File Sheets = dimensions are 2 3/4in. x 17 1/2in.
#2. Lock it in first gear.
#3. Have an assistant (slow and steady) rotate the output flange.
#4. Work the sand paper (light even stroke/pressure) on the bearing pilot surface like a shoe shine, three revolutions.
#5. Stop, dry wipe the pilot shaft and test fit the bearing.
#6. Note: The bearing should be light contact, not a tight - hard fit.
#7. Repeat steps #3 through #6 as needed.
#8. Lubricate inside the bearing, and the pilot shaft with a light (skin) coat of Wheel bearing Grease.

Triple check the pressure plate, many after market units claim to fit the MB flywheel, when they are actually a few hundredths of an inch to wide = they fail to fully seat = set cockeyed, but can fool a visual inspection.
Always measure the seated height at three or more locations, BEFORE you try installing the transmission.

.

charmalu · #8 10-18-2013, 12:30 AM

Thank You Roy for the info.

I have a second new Pilot Bearing, and it slips right on the out put pilot shaft. not a tight fit.

The bearing in the crank hole center sleeve will not turn freely when I stick my finger in it. as does the one in my other engine that is on a stand. put my finger in it and turns smooth as butter.

As difficult as it was to drive the bearing in, this gave me a clue to the smaller crank hole. and think maybe it squeezed the bearing enough so the center sleeve doesn`t turn.

Maybe before removing the bearing, I`ll polish up the out put pilot shaft and see if that will get her to slip in.

If the center will not turn, that wouldn`t be any different than if there was a bushing installed. As it all rotates together, and just supports the Input Shaft.

I did think of using the bolts to pull the transmission onto place, but quickly dismissed that idea. If it is tight getting he on, what about ever having to remove the transmission?

Charlie

Dan Stokes · #9 10-18-2013, 08:51 AM

I went thru this with my swap and posted it in my build thread. I did the same deal - carefully work the hole in the crank larger with a tootsie roll. I posted the dimensions in my thread in inches - forget the numbers off the top of my head.

I suspect that another option is to take the bearing (SKF 6202-2RSJ) to your local bearing store (most towns of any size have one) and have them give you a bearing with the same dimensions but a 34mm OD. I'll wager it's a standard bearing. This pilot bearing is nothing exotic, just a standard double-sealed ball.

After I pounded mine into the modified crank hole (still a bit of a fug snit) I found that the input shaft was still snug into the center of the bearing. The trans did not want to rotate with the levers in neutral. A tap on the rear of the output shaft and everything was fine - this just drives the input a bit into the pilot bearing.

I think that the bushing would work fine too. Virtually all American cars have gotten along fine with bronze bushings for decades.

EDIT:

I forgot to mention that I had to buy the bearing puller attachment for my slide hammer. The only one that works is the type with arms that spread inside the ID of the bearing. I don't recall the other type that I got from Advance but the little arms that were supposed to grab the bearing just pull thru.

Here's a pic of the one that works. I got it at CarQuest.

Dan

whunter · #10 10-18-2013, 02:48 PM

Here are many different types of pullers.

http://www.peachparts.com/shopforum/general-information/345164-blind-hole-pilot-bearing-bushing-pullers.html#post3225317

.

charmalu · #11 10-19-2013, 01:17 PM

Yesterday I decided to do as Roy suggested, to have my lovely assistant turn the out put shaft of the Transmission as I held the 180 grit sand paper on the Input Shaft.

The Flex Disk is still attached to the rear of the Transmission, I placed a 6" long bolt in one of the holes for her to turn the Shaft. makes it easy to turn it at a steady even speed.

Did a couple trial fits and the shaft would sort of go in slightly. then got the brilliant idea to use the Dremel with a 1/4" barrel sander to go around the inside of the Pilot Bearing to slightly open it up. after 3 trial fits, it went right on right up to the adaptor plate.

OH Iam so smart.

Placed the Clutch Disk on with the alignment tool, and then the Pressure Plate. Torqued it all down, and installed the Transmission. HMMM still won`t go the last inch or so to the engine.

Now my thinking is that the Pilot bearing being too large for the crank hole, and forced in, squeezed the outer ring into the Bearings which squeezed the inner rotating Sleeve of the bearing. Also the PB could be slightly out of line (not square) with the flat face of the Crank. the alignment tool lines up the Disk with the hole in the Bearing and the Splines of the tool. then after torqueing the PP and installing the Transmission, my thinking is, that the Splines are slightly out of line with the Disk because the PB is slightly out of line or tilted ever so slightly.

Using the Dremel on the inside of the PB will open it up, but it`s really not a good idea, as we will now have the Steel Input Shaft inside a Steel Sleeve which will not rotate with the shaft as designed. And there could eventually be a possibility of the shaft being galled and a heat build up.

As Roy mentioned up above he used a Dremel..........
I gently used a dremel with 180 grit barrel sander, to clean the crankshaft bore

And Dan mentioned this in his post above.......
I went thru this with my swap and posted it in my build thread. I did the same deal - carefully work the hole in the crank larger with a tootsie roll.

Going with this method, we are talking about one Millimeter of metal between a 85 crank and all the other ones built all over the world since about 1976.
Trying to take off this small amount of metal by hand grinding seems kind of Iffy to my primitive Brain.

My thinking now is to pull the bearing and have a Bronze Sleeve/Bushing made to fit. With the FW now bolted on, my calipers won`t work to measure the Crank hole to get a official size. would have been easy before the FW, but I had it on before driving in the Bearing.

My machinist friend said to bring him the crank and he will machine it to the size, and we both knew that wasn`t going to happen, now if we were building up the engine would be different.

I Tongue in Cheek said "why not fill the hole with JB Weld, slap on the Trans, turn the shaft as it is setting up so not to stick?".

Sorry to be long winded here, just sort of my thoughts as Iam going along here.

Charlie

junqueyardjim · #12 10-19-2013, 01:45 PM

Charlie, I have no idea what is going on. Are you positive that you have the correct bearing? When you discovered it was difficult to get the bearing in the bore, did you at that time not check the shaft hole size against the end of the main shaft? It is hard to believe that one would not check that. Well, I know from experience that you can knock that bearing in the hole of the crank of a 1985 617 engine, but not without freeze shrinking it. I shrunk mine in the freezer for 24 hours and had a "weather warmed" engine sitting in the sun light on about the 4th of July. That one mm difference in size as I recall is about 35 thousandths, and that is a lot of squeeze when it come to steel. Without freeze shrinking I am sure the bearing would break up in forcing it in. And even then, though it started in easily, it soon pushed hard and took a couple of pretty good hammer blows to get it to the bottom. The transmission shaft, "which I had previously checked" fit to a "T", so no problem there at all. I do fear that someday the pilot bearing will have to be removed, and I do suspect it will be difficult. But it is going on 4 years since, and all is well.

Frank Reiner · #13 10-19-2013, 03:33 PM

Quote:

Originally Posted by vstech

I find it difficult to believe you could hammer a full millimeter difference bearing into the hole...

I concur.

1mm=.03937"
The crankshaft will have a hardness of ~Rc 40 in the pilot bore.
The bearing outer race will have a hardness of ~Rc 64.
A very tight interference fit at a diameter of 35mm would be .002".

At an interference of almost .040", there is absolutely no way that the bearing could be inserted, even with a large press, while still intact. The outer race would be shattered.

Dan Stokes · #14 10-19-2013, 05:47 PM

I DID get mine started but it wouldn't seat properly. This was after I took the edge off the bearing on my green wheel (a mild abrasive wheel that does magic things) and froze it.

I then went to opening up the crank ID with the tootsie roll, which worked. As you surmised, the issue with this method is that you're assuming that you kept the crank hole round and concentric. My guess is that it'll be close enough but it's unlikely to be ideal.

But if I had it to do over again it would be off to the bearing store for a bearing with the smaller ID - I simply didn't think of that at the time. This actually handles the issue properly and will for sure be cheaper than having something machined, though that will probably work fine, too.

You can also order the bearing online but I don't know how long it would take to get it.

EDIT:

A little on-line research on the 6202-2RSJ bearing. It's 15mm. ID, 35mm. OD and 11mm. wide, double sealed. I didn't search for one that was 34mm OD but it's likely that there's one out there. Your bearing house ought to be able to find one for you.

Dan

charmalu · #15 10-19-2013, 09:10 PM

The bearing I stuffed in the Crank is Part# 115-980-01-15. a SKF bearing. the other # is 6202-2RSJ. 15 x 35 x 11 MM. It`s nothing MB specific, just a run of the mill bearing used in a lot of applications.

I have been searching on Google and looking in various Bearing supply places, there seems to be no bearing the size, 15 x 34 x 11mm.

Though a few minutes ago I did find this site that shows a 15 x 34 x 11 bearing for $1.50.

15x34 Bearing 15x34x11 Metal Bearing 6202ZZ

I rented the Pilot Bearing puller like Dan shows in an above post from Auto-Zone. Dan I don`t know how you got it in the hole of the bearing, but it is too large to fit in there. Even tried my spare FAG bearing in my hand, and a no go.
So back to AZ and see what else they have, with my spare bearing with me.

You guys are probably right, there is no way I could have pounded this bearing in a 34mm hole, but it is in there, and squeezed tight so the center will not turn and the Transmission Snout would not slip in until I Dremeled it out some.

Iam looking for a Bore Gauge so when it is out I can get the official inner measurements.

Charlie