1276 Transmission HELP Needed

[1276Beast 3]

I am currently towards the end of a 1276 restoration project, I just got everything back together and sent power to the transmission for the first time. Without the pump on and the gear in neutral, I can spin the axels by hand, one goes one way, the other, the other way, giving me indication that I don't have a differential problem. When I put power to it, everything appears to work as advertised, except when in gear I can stop the Axel from spinning with my hand, little to no resistance. I do have a bit of a rigging problem from worn linkage, but I can move the cam by hand to get it fully in gear. The tow gear in completely closed. Just flushed and filled with fluid. I have not changed the filter. 

 

Any idea on why there seems to be no power in the axels??

[953 nut 68,780]

My guess would be that you opened the "Tow Valve" at some point and have not re-closed it.

Edited March 28, 2017 by 953 nut

[WHX?? 57,900]

My guess is you have a choice resto happening there and we like it!

 

 

[1276Beast 3]

After reading through these forums, the first thing I checked was the Tow Valve. It was completely closed, I then opened it and reclosed it to verify. No joy. 

[WHX?? 57,900]

Given your obvious skills you checked all the "duh" factors like hub keys and such?? I am not a pro with a 1276 but bet my bottom dollar ther are guys here that are and they will be along.

[Ed Kennell 47,106]

Did it work OK before you flushed it?

[1276Beast 3]

Hub keys are good. I just replaced the axel seals and installed them the other day. 

 

As as for the flush, it seemed to work the same before as it does now. 

[SPINJIM 1,997]

When you grab the one axle by hand, does the other axle speed up ?   If 'yes', then I think that's the way the differential is supposed to work.  It is not a 'limited slip' differential on the 1276.  If you can stop both axles by hand at the same time, then you have some other problem.   I have a 1076, but have not taken the trans apart, so someone more experienced might correct me.

   Jim

[Ed Kennell 47,106]

So, I think you are saying this was not a working transmission when you got it and a flush and refill did not fix it.

Can we assume the input pulley key is OK and the pulley is not slipping on the input shaft.

What was in the unit when you drained it...oil or ATF?

What did you fill it with?

[WHX?? 57,900]

In case you don't have it. Note the type of fluid and capacities in it. @achto has a 1076 with a Sunstrand maybe he can shed some light on your problem.

[pfrederi 21,095]

10 hours ago, SPINJIM said:

When you grab the one axle by hand, does the other axle speed up ?   If 'yes', then I think that's the way the differential is supposed to work.  It is not a 'limited slip' differential on the 1276.  If you can stop both axles by hand at the same time, then you have some other problem.   I have a 1076, but have not taken the trans apart, so someone more experienced might correct me.

   Jim

 

Jim is on target here.  From your narrative it is unclear if you tried stopping both axles simultaneously or just held on to one....

[Sarge 3,473]

As long as the tires/wheels aren't loaded with weight - it should be pretty easy to stop one wheel on that trans model - it's an open differential and the early bevel gear design , like used on cars/trucks . Specifically , it's a simple 2-pinion of sorts and uses some pretty heavy bevel gears . In all the years I've had my 1277 , not one problem with that differential and I've pushed it well past reasonable limits - broken the frame mounting plate three times now with heavily loaded tires , lol . Biggest no-no with that style differential is to allow one tire to spin at high speed , then suddenly stop it on bare pavement or something - in a car , that results in an exploded diff gear in a hurry . Learned that lesson the hard way in my first car but the old Dodge was an easy fix .

 

The biggest thing you need to test is the strength of the Sundstrand pump and hydro motor that drives the transmission gears - when it's up to full hot temperature it should still easily spin the tires if it's in good shape . Don't be afraid to flush a couple rounds of oil through the trans along with a new filter each time to get any sludge out and dirt - keep it dead clean or trouble will result . Hopefully the intake screen isn't plugged or broken off - that spells death for some of the pump parts and @daveoman1966 has done some nice detailed posts on that model as to rebuilding the pump . It should be using regular ATF fluid , but some were changed later to motor oil so pay attention to what was in it , color and odor - ATF has a very distinct odor and easily detected , even when very old . The biggest issue with the Sundstrand was how previous owners took care of them , or lack thereof ...most never got their yearly oil change as specified in the manual .

 

Sarge

 

 

[Achto 32,462]

22 minutes ago, WHX9 said:

@achto has a 1076 with a Sunstrand maybe he can shed some light on your problem

 

I was lucky with my trans and did not have to tear it apart so my knowledge is limited on these. All I did was change the fluid & filter & life was good for mine. I have been following this post hoping to learn something.

[1276Beast 3]

First off, thank you all for the posts. I have learned a lot from this site! 

 

I got the wheels on today and fired her up. She ran flawlessly for about 15 minutes. The transmission issue I am having just seems to be a simple rigging problem as the cam seems to be warn. But none the less the transmission is strong as a bull!

 

Now I need to figure out why my carb started pissing fuel out of the intake, even after a rebuild. 

 

Again, thank you all for the helpful insight. I'm happy to be apart of the Wheelhorse community and look to many happy years with my horse!

 

Jeremy 

Edited March 29, 2017 by 1276Beast

[WHX?? 57,900]

Your welcome from all of us  Jeremy, carb issue something as simple as a stuck float or other crap in ther? It happens after a rebuild...good luck!

Edited March 29, 2017 by WHX9

[pfrederi 21,095]

Make sure your float does not have gas in it