Suburban Tranny Carnage

[Racinbob 11,237]

I hear that. I made the splined axles work but never tried the later diffs. I wish I had the goodies to play around with.

[Achto 27,818]

We still have not come up with a way to get the diff housing to ride on bearings. 

[WHX?? 49,182]

I was thinking just weld a back plate on and bolt up a two piece three speed....  I have one of those in stock too! Biggest problem right there would be how to grow moss on the new tranny!

[stevasaurus 22,878]

Your one problem Dan, is that bull gear is shot.  In looking at your pictures, your brake shaft gear is the older style (8 teeth on the upper shaft)...I think your bull gear differential is the newer style and that would never mesh with your brake shaft gear.  That is why you see all the wear on those teeth.  A couple of pictures of the teeth on both of those would verify what I am seeing.  Somebody has been in there, if that is the case.  If I am right, and your brake shaft gear is OK, you are going to have to find a matching bull gear differential...earlier style.  The other option is to replace both the brake shaft and differential with the newer style.     What a difference a Margarita makes. 

Dan, what I said above would get rid of the bronze and put in needle bearings.  It is very tight in the 3 piece trannys, but the newest style bull gear is the same in each of the types of trannys.  It will come down to the width of the differential and if it is about the same width as the 3 piece, anything is possible.  Mounting a plate and bolting on a #5025 is easy also...lots of linkage to modify. 

 

[Achto 27,818]

22 minutes ago, WHX12 said:

 I have one of those in stock too! Biggest problem right there would be how to grow moss on the new tranny!

 

A light sand blast to get some rust started & a good coat of used oil should make a new tranny look right a home.

[Achto 27,818]

Can you guys check this out. https://www.partstree.com/parts/toro/parts/703255/

Is that the right diff carrier? The number on mine is 3502.

[stevasaurus 22,878]

Dan, 3502 looks to be the correct differential.  The Service Bulletin can be confusing.  Take a couple of head on pictures of both the brake shaft upper (I see 8 teeth)  newer is 11.  and the differential bull gear...I thing the newer one is 44 teeth.  I can tell the difference if I see the pictures.  Dan, take a look at this video around the 3 minute mark..  this is where I explain this stuff.  You will know what you have and what you need after seeing this. 

 

 

[WHX?? 49,182]

Tractor 1960 400 550 IPL _A-7136.pdf

I cannot believe that that part would still be available but some places I look says it is and other , like jacks small engine says its not.

https://www.russopower.com/parts/toro-703255

https://www.jackssmallengines.com/jacks-parts-lookup/part/toro/3502

 

Maybe Smoken Joe has another set stashed around or possibly Jake Kuhn?

 

His pics looks like he would have the old style?

Edited August 10, 2017 by WHX12

[Achto 27,818]

@stevasaurus , my brake shaft has 8 teeth, & my diff carrier has 31 teeth. The carrier has 3502 cast into it.

[Achto 27,818]

Last night while cleaning my tranny parts, I think I may have finally found what caused the tranny to lock up and snub the engine. One of the cluster gears had a piece of metal jammed into the teeth. I had to use a chisel to knock it out. The gear does not look like it suffered any damage, nor does the gear that it meshes with. Sorry, forgot to take a pic.

 

Here is my plan of attack... I think. Replace the damaged parts, all new bushings, make new axles & put it back together stock. I could customize it to have bearings on the axle out by the wheels, but the diff would still be riding on bushings. The diff bushings show a lot more wear than the axle bushings do, so I don't see a huge gain by only changing the axles over to bearings.. If something like this ever happens again, I'll probably switch to a 2 piece 3 speed tranny. 

[WHX?? 49,182]

Sounds like a good plan ...any luck on locating a new carrier? I know some guys who know some guys! Bushings can be easily had & i've got some of the bearings if any bad that are good.

[Achto 27,818]

Still working on the parts. The diff from Parts Tree is a bit confusing.

 

When you look up the part using the parts diagram it comes up like this.

Toro 703255 (replaces 3502) Diff Case & Gear   When you go to order it comes up like this. Toro 703255   BEARING REAR AXLE   I really wish that they had a picture of what your getting.

 

[WHX?? 49,182]

Wonder if you could drop a dime to those places who say they have that part? Would be nice to know if it's the new style with more teeth or the same as what you are replacing. My bet is they are gonna say "oh..we're sorry that part is NLA" . I will fall off my barstool if it is and especially for those prices!

[stevasaurus 22,878]

Dan, the way I read the service bulletin...with you having both of the older style differential and brake gear shaft...they upgraded to the newer style.  It states that if you have the older style and need one of those parts (like you do), then you have to order both of the newer style parts.  If you can find an older style differential, it is probably going to have to come from somebody on this site. 

   BTW...those are matching p;arts that you have.

[lynnmor 7,354]

I know little about earlier transmissions.  Near the beginning of this thread it was said that the axles aren't hardened.  If it has a needle bearing, the surface that the rollers run on needs to be hardened.  I know that the later models have needle bearings and the axle is induction hardened only where the needles run.

[WHX?? 49,182]

Thanks for the reminder Lynn... we were just kicking around  the what if we did.

[stevasaurus 22,878]

@lynnmor is correct in what he is saying.  The 3 piece transmissions use bronze bushings for the axle bearings...these are not hardened. 

[Achto 27,818]

Started repairs on my tranny tonight. One thing that I noticed was that my axle tubes were not square with the side plates. I'm guessing that the 23x10.50x12 tires may have contributed to this issue. The weld on the left tube was even cracked. After pulling the tubes back into place I welded in some gussets to keep this from happening again.

 

I was able to get my new axles made also. Instead of cutting them for half moon keys, I cut straight key ways in them. The sprocket end is cut as a pocket, the hub end will take a 2" long key.

 

Some parts showed up in the mail today too so I'm hoping to assemble real soon.

Edited August 24, 2017 by Achto

[PeacemakerJack 10,739]

Looking good Dan! You'll have that Dude pulling wheelies again in no time!

[Achto 27,818]

Wed. I received my new diff carrier & brake shaft in the mail. These are the upgraded set with finer teeth. Some rust on the parts but they look to be in good shape.

 

After blasting them with glass bead they cleaned up nice. Some pitting but much better than what I had.

 

Hopefully my bearings & bushings will be in today so I can button this back up this weekend.

 

Edited August 25, 2017 by Achto

[stevasaurus 22,878]

Perfect Dan...a sight for sore eyes.    That is about as good as you will find out there.

[Achto 27,818]

Unfortunately my bearings did not show up yet.@WHX12 made a suggestion that I should install a magnetic drain plug. I dug through my boxes of goodies & found a drain plug from a HD primary case. I think it should serve my purpose well.

 

Now I'm sitting here with all my parts sterilized just waiting for a few bearings so that I can assemble.

[PeacemakerJack 10,739]

I hate those "hurry up and wait" situations.  Great call @WHX12 on the magnetic drain plug.  I have those in most of my K series single engines.  Great place to collect any stray metallic debris and keep it from circulating through the gears, etc.  I think it is also cool that you incorporated a piece from another one of your passions (the motor company)

 

The Rat will be back alive again soon!

[WHX?? 49,182]

It's just plain stupid not to do it when you have it apart .... for what a lousy 5 bucks in magnets off eBay to do a dozen or a dig in your BS bin??? Not original for sure  for the purists but for customs??

[Achto 27,818]

It's been a long wait but I was finally able to put my Suburban back together. A BIG thanks to @Racinbob & @groundhog47 for setting me up with the parts that I needed and to my friends Jason & Scott for use of their lathe.

The reason that the repair took so long was thanks to my supplier for the bearings & bushings. The bushings for the dif carrier were the big hold up. I finally just asked for any 1 1/2"o.d. bushing that they might have in stock, this actually worked to my advantage. On my first attempt I bored the i.d. to the stock 1.375" and this ended up being a little too loose of a fit. I had plenty of material to make two more so I ended up boring the i.d. to 1.367, this was a snug fit. After pressing the bushing in to the diff carrier it would not fit on to the axle sleeve. A few passes with a brake hone cured this issue and gave me a snug fit with slight resistance when rotated. Then it was off to final assembly. I started final assembly Thurs. night at 7:15pm and.... to the dismay of my neighbors, was test driving it around 12:20 . Assembly would have been faster if the wife hadn't insisted that I stop part way through to eat supper. Happily though it was able to come along to a show with me on Fri. morning. Very happy to get some seat time on this lil tractor again.