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

Diesel911 · #10 10-20-2013, 08:20 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

Use a Telescopic/Snap Gauge a long with the Micrometer. Your Friend that made the other Pilot Bushing may have one in the size you need.

They also make them with longer handles.

charmalu · #11 02-27-2014, 03:09 PM

After procrastinating on this pilot bearing problem, I decided to load up the engine and take it down to my machinist buddy so we could measure the crank hole. He use a telescopic gauge, and came up with 1.371" or 34.78mm. Then measured the Pilot Bearing and came up with 1.378". so the Bearing is 7 thousands too large.

luckly I had a few bearings on hand, and by the third one we got it right.
First tried to use his lathe, but ended up using a belt Sander with a narrow belt. holding the bearing in his fingers and putting a slight drag on the outer part with his Thumbs, he finally got it.

First two that seemed to go in, but were just slightly too tight. pulling them out with a puller put enough stress on the inner ring, that they had a slight roughness to them.

Lots of grinding, measuring etc... to finally seem like he had it. Didn`t want to take off too much or too little.

Finally got the third one to fit just right. When he installed the Bearing, he drove it in as far as it would go. Didn`t think about it at first till I was installing the Disk and Pressure Plate when I got home.

Now back up about 3 yrs ago when I first swapped in the 4-spd, I put in the Pilot bearing more or less flush with the face of the Crank. Installed the Disk, PP and Alignment tool, it all went together and the transmission went right in.

Now with this one with the Pilot Bearing in as far as it will go, there is some up and down movement with the Alignment tool, and the Disk moves with it. There should not be any, or the transmission Splines will not line up with the Disk.

I had the trans on and off several times, moving the Disk so slightly, and with just 2 Bolts holding the PP on thinking if it was on just enough to hold the Disk, the Trans splines would move the Disk to line it up. Maybe with only the 2 bolts instead of the six, it wasn`t holding the PP close enough.

So finally added the 6 Bolts and finally got it lined up enough the Trans Splines felt like they were going it. Got the trans in up to about 1/4" from the Adaptor Plate. used the trans Bolts and pulled it in the rest of the way. Maybe not the most desirable way to do it, but it is on. Now need to remove trans and torque down the 6PP Bolts.

The slight up and down movement of the Alignment tool Iam thinking is because the BP is in too far, and not enough of the tool is buried into the bearing.
After sleeping on it last night, my thinking now is to see if I can pull the bearing out closer to the face of the Crank. And W/O damaging it. I do have 3 new bearing left to play with.

Hope I explained my actions and thoughts here and not being too long winded.
I tried not to leave any unanswered steps or to confuse the reader, except for the confused one here...me.

My original plan was to get Dan to measure the Crank Hole, and then buy the Bronze to make a Bushing.

Charlie

Frank Reiner · #12 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 · #13 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 · #14 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

whunter · #15 10-19-2013, 11:34 PM

Quote:

Originally Posted by charmalu

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

Depending on how much material needs to be removed, this may work.

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