Overhauled Suburban Tranny or ??

[oliver2-44 9,875]

@stevasaurus @Racinbob

I finally had time last weekend and got my 3 piece Suburban tranny assembled last weekend.  You could not turn the bare axle or input shaft by hand, but with the input pulley or a axle hub on it it turned nicely but a little snug. Everything was bead blasted and all new bearings and bushings.  I had honed the axles bushing to a oiled just slide fit so I though I would run it in with an electric motor. Also thought the run in would help "wear"  the gears from 3 different tranny's together. The axles were flipped and holes drilled for the axle gears. I also used the right side plate from an RJ tranny due to the side of the input bearing boss being heavily rusted. so here's it on the test run.  IMG_4252[1].MOV    Yes that's the tranny making that sound, not the electric motor or wash machine!  I didn't expect this tranny to be the quietest.  I went ahead and ran it in each gear for about an hour, so about 4 hours run in time.  It got a little wardm as expected, but I could easily hold my hand on the case or side-plates in any place  I then sampled the oil and saw lots of shinny metal glitter. I drained the oil, and rolled a strong magnet around in the drain pan.  I got lots of very very fine metal dust, no  shavings.  The clumps in the pic or fine but stuck together with oil.  the metal wear is almost the size of pencil lead dust.

 

 

I decided to pull a side cover for a look, and didn't see much but some wearin gin on the large diff gear.  As the pictures show, about a lot of the gears have pitted tooth faces, but all of them had fairly good tooth profile. In these gear pictures I've tried to show the worst area of each gear.

 

 

 

 

 

Below id the diff gear with the new "Wearing-in areas.  On all the other gears I saw a few tiny wearing-in  spots but very little. If you look at the diff gear above, you can see a faint amount of "polish" wear where it rides with this gear, but really very very minor.

 

Below is the left side plat which came from an RJ transmission.  I had filed the inside edges of the axle tube smooth, but there is quite a raised edge on the inside and outside edge of the tube.

So the first thought is the axle tubes are some how being pushed against the side of the axle gears inside the differential.  i checked the "length" of the 2 inner axle tube and the left (RJ)  is 1.540 and the right is 1.490.  I then checked the other 2 side plates I have and the both measure around 1.490.         
 

 

 

 

Below is the right side plate which is original to this case.  The axle tube hase some raised edges, but not as much as the left plate.

 

 

below I checked and I have about 0.012 ths clearance between the 2 inner diff -axle gears.  As I mentioned the axles were flipped and I took the to a friend and drilled them on his mill to get them straight and spaced from the ends just like the holes on the original ends.  

 

 

 I measured the depth of the differential (where the axle tube goes in) and the length of each axle tube

                   Diff Depth   Axle tube length

Right Side:  1450            1.510 

Left Side   : 1.450            1.495

So this looks like burred axle tubes can ride deep enough to rub on the ends of the axle tubes.

The Case is 5,975 wide

The Diff is     5.920 wide

 

So there should be about 0.055 clearance (0.0275) per side between the side plates and the ends of the diff.

Since I cannot get a measurement of the width of the 2 axle gears inside the case......  

 

The cable guy just came to work on my slow internet speed so more late

 

In the mean time give me your thoughts>>>>?????

 

 

 

My thoughts are I'm going to   

 

 

 

[stevasaurus 22,881]

Gees Jim, that is one nasty transmission, but it should be OK for riding around and maybe mowing a lawn.  For some reason, I can't play those MP-3 videos.  That's OK...I now what one of those sounds like when it is tight.  If it was me, I would hone the outer axle bushings a little more, you should be able to turn the axle by hand easily...you said you could turn it once the pulley and hubs were on...that means you are close.  I also noticed that some of those bearings are maybe not seated to flush with the top of the rings...could be the pictures, pictures have a habit of making things look worse then they are.  If any of those bearings are not flush in the race, it will make the trans tight and bind also.  One other thing I would do...put about 1/2 qt of Lucas Oil Treatment (it's like STP) in there with the 90wt.  You should be OK with that in Texas.  

   Actually, I'd be more worried if that trans did not make any noise.  You should hear me with my bad knees...I can't sneak up on anybody on stairs.  The Lucas Oil treatment will quiet the trans a little and cushion the gears.  One other thing...check the bottom of all those gears (between the teeth), if you see any little specs, file them out.  It does not take much in the bottom between those teeth on the gears to make things mesh correctly, and quietly. 

[Racinbob 11,238]

Try this free player Steve http://www.videolan.org/vlc/

 

That is pretty loud Jim. Is that chattering I hear? It was hard to tell with it being only 3 seconds long. Hopefully Steve can listen so we can get his 2¢ worth.

[oliver2-44 9,875]

Well i took a couple of hours nap in preparation for going in to work at 10 tonight.  We're staffing the dams I work at in case we get heavy rains from hurricane Harvey.  I suspect we really won,t  see much rain until tomorrow daytime.  But that means the Saturday night shift could be busy.  We're fare enough from the coast that we won't have the  very high winds or heaviest  rains,  but even 5 inches of fast rain in our rocky Texas Hill country can be a flash flood. 

So I've got a few hours to work on this tranny..   

 

With everything back apart I filed and polished the burs back off the ends of the axle tubes.with the heavy ridge I found on the bottom (left) axle tube and rubbing on the axle tube where it fits in the diff .  I think the diff was binding on the axle tube. i suspect that why the diff gear teeth are showing the wear - the pinion is having to work to push the diff teeth.  So, I reassembled the case, differential and side plates (no other gears).  It all  rotates freely with the bottom side plate tight, and the top side plate bolts barely snug.  But, when I begin to tighten the top side plate bolts up more both axles tighten up. I can just barely turn then by hand with all the grip I've got.   I'm going to make a 2nd gasket for the top side plate to see if that changes anything. If it doesn't I'll hone the axle bushings a little more. Before i put the top plate on I checked the clearance between the top side of the diff and the case height. its only about 0.007 ths.   Thais tighter that I thought it would be,, but when you think about it, there's nothing but the axle side plates centering the diff in the case. 

 

 

 

 

[953 nut 55,873]

24 minutes ago, oliver2-44 said:

We're staffing the dams I work at in case we get heavy rains from hurricane Harvey.  I suspect we really won,t  see much rain until tomorrow daytime.  But that means the Saturday night shift could be busy.

I feel for you, worked as a Nuclear Power Plant operator for several years in Florida and had to work the majority of the hurricanes; double shift around the clock for days on end and have no idea what is going on at home. Don't miss it a bit. 

31 minutes ago, oliver2-44 said:

when I begin to tighten the top side plate bolts up more both axles tighten up.

Could one of the axle tubes be a little tweaked?

[stevasaurus 22,881]

It is possible that the tubes are not straight...I almost doubt any of them are.  I can't stress enough the honing out a little more on the axle tube bushings.  I can't tell you how many times I have taken these apart again and had to do that.  It doesn't take much, but it sure makes a difference.  Jim, a second gasket may work, but remember you are adding another 1/32" of slop to the whole tranny. 

 

Thanks for that link Bob...I can open the MPG's now.    After listening to the tape about 12 times, I think I was hearing a clinking going on inside.  Was there oil in this trans in the video??  The video needs to be longer to  really get an idea of what is going on...moving the mike around it also might help.  Jim, if you still get that sound after putting it back together, use a long screwdriver as a stethoscope to listen at different places around the trans.  My guess would be the differential bull gear and the meshing of the mushroom gear making the noise and after looking at those teeth...plus that area being tight. 

[Racinbob 11,238]

That's exactly what I was fighting Jim. With the side plate bolts just butted up it spun freely. But tightening them put a bind on things. I had the thing apart at least a dozen times trying things including a second gasket. Finally I honed the outer bushings a fuzz more and all was good with the world. 

 

I'm glad you got to hear the video Steve.  Something about that noise just doesn't seem right.

 

[oliver2-44 9,875]

 I honed both axles a sight amount as @stevasaurus and @Racinbob recommended and the diff axles turn freely in the case.  So the lesson is the axle bushings need to be honed to provide just a tiny bit of up and down wiggle instead of being a perfect sliding fit.  As I was putting it back together for what I thought was my final assembly I discovered another problem.  I had installed the cluster shaft and gears which is the last shaft and gearing to install.  As I was putting the top sideplate on I had to reach under the plate to align the cluster gear shaft with the top plate and it had a lot of wiggle.  Then it occurred to me that the cluster gear shaft had dropped into the bottom bearing easily every time I had assembled it ( Yes I'm becoming very good at test assembly)  Taking the cover out of the way I found I could easily rock the cluster shaft in the bottom bearing.  This shaft came from some other spare parts and I used it since it had a slightly better cluster gear.  I dug out the original cluster shaft and the bottom end is about 0.004 ths larger than the shaft I had been using.   I also test fitted this shaft in a spare SK* bearing and it was a tap in smug fit.  So part of the noise probable was the cluster gear bouncing around due to the shaft being loose in the bottom bearing.  I had to stop at that point, so my next task is to polish up the original cluster gear shaft and finish the final assembly.  Regrettable it may be a few days until I get back to this.

[stevasaurus 22,881]

You gotta love these transmissions...after a couple of times of tear down and put back together...one can do it in around 5 minutes.  Good to hear you got it figured out Jim...sure would like to hear another (longer) video of it on that test bench.  Remember the Lucas Oil Treatment.