We have had a lot of rain lately. My speedo started under-reading. I removed the trans sender and cleaned it up, greased the elbow etc. Don't know if it is better,,


BUT while looking at the unit from the rear of the tranny, I noticed what I thought might be a dust cap which was trapped in the U-joint yoke. On closer inspection,

.it seems to be a retaining nut and a tiny bit of the transmision output shaft.


There have been a few drops of transmission oil on the driveway. This happens from time to time and since I overfill the getrag quite a bit, I have never worried about it. There is no real leak I can see back there but it is hard to tell with rain soaking it.

Question #1

Could I be right about the output shaft snapping a half inch from the end? I have had the truck for 18 months, never touched this area. I did have the drive shaft off when I changed the pinion seal, so the snapped end (if this is what it is) could have happened anytime in the last year.

Question #2

How serious is this? I pull a 6000 pound fifth wheel and am planning a trip to Minn. in a few weeks. I think I might have to tear it down before but obviously would like to avoid it if I can.

The transmission has always worked well. It vibrates a little in the lower gears if lugged but I try not to do that because I was told getrags don't like being lugged, especially under load

 

I would certainly pull that u-joint out and confirm whether or not the shaft broke. I wouldn't drive it like that, let alone pull a fiver.

 

I am betting your speedo didn't start to read incorrectly 'till the shaft popped, at which time the speedo drive gear began to slip on the output shaft.

Next think you know, the output yoke will fall off, and you will end up trashing your drive shaft and whatever else. . .

The whole scenario looks as though it really stinks. Hopefully I'm wrong, but regardless, I think that you need to check it out before heading out of the driveway, let alone taking a trip.

 

I am certain you are right Alec. I will park her till I get it fixed. I guess what I need now is a rebuild kit and the shaft which snapped off at the end. My guess is that wear in a bearing or bearings let the shaft move, stressing the nut which retains the yoke. The end of the shaft snapped and I guess it is better that it did it on the outside rather than on the inside where other parts and maybe everything would have come apart.

Does anyone have the shaft? I have seen rebuild kits out there including one on ebay and will try to pick one up.

It is in fourth gear that the most vibration was felt

 

Sounds like the nut is loose. This would splain why your speedo is wrong. Take the driveshact loose and torque that main nut to 200-300 and it'll be fine. If the shaft snapped you would be dead in the water, I think you'll fix it easy.
-Jim-
Unless it really is broken, but that is a really big high torque shaft. There is a core for sale on ebay for $400 which is probably cheaper than a mainshaft.

 

The nut is caught in the yoke with a tiny piece of the shaft still in it. The nut is not very deep and the piece of the shaft still in it is not even as long as the nut is deep.. The yoke has pulled out a little bit and the remaining shaft is now flush with the face of the yoke. I must pull the tranny and change the shaft. The nut may not have been fully torqued down. The broken bit of the shaft does not protrude past the nut.

I am curious about how much of the shaft normally sticks out beyond the nut. If it had loosened and stuff started moving internally, it might explain why it snapped.

At this point I am still just guessing. It sounds like a good time to pull the tranny anyway and give it a real good look over.

 

This trans is a core and he has no bids. I would watch it and see if he gats any offers. If not you could contact him after the sale and maybe offer $200 or something. You may need it.
http://cgi.ebay.com/ebaymotors/ws/eB...category=33733
-Jim-

 

Last time I looked at mine, it doesn't stick out beyond the nut at all - the end of the shaft seems to be almost flush with the end of the nut.

 

That is the way the set-up on mine looks. There must have been some serious thrusting in the shaft for the end to break right at the nut.


Thanks for the information Jdonoghue.

Does anyone know if this shaft is the one called a 'cluster shaft' in a parts diagram on the web? It is available for about 30 USD or so.

Also can anyone post or send me some information or instructions on the removal and rebuilding of the getrag?

Up front it looks like I will need a rebuild kit, the shaft and possibly a fourth gear synchro (once in a while it would grind if my third to fourth gear shift was a too slow) It seemed quite good enought though, and it the part is reall spendy I will leave it alone. It never, never jumped out of gear.

A good souce for parts (new or used) would be appreciated ... especially one in Canada.

 

Sorry I can't help you find the parts, but hopefully I can help with some naming:

Where is that parts diagram?

 

A lot of water has flowed under the bridge since this morning. Standard Gear of Texas put me in touch with an outfit in Edmonton called North American Power Train ...... They told me that they have everything I need. The mainshaft is about 300 CD and the rebuild kit is roughly the same price.

The fellow from Standard Gear said that it is not unheard of for the end of the shaft to break in a high mileage Getrag.

I am going to tear it down this weekend and pickup the parts on Monday. I knew the old tranny was going to need some care and am real glad that I identified the problem AND that you guys told me not to drive it with the yoke loose.

Thanks again. I will keep you posted on how the repairs go. By the way, I am flying without a net on the tranny disassembly. I have done this sort of work on old volvo gearboxes years ago but any advice would be appreciated.

I have already used the pressure washer to try to minimize the crap falling into my eyes under the truck. Seems like a straight forward job. I plan on using my crawler jack to raise and lower the transmission.

Thanks

 

I pulled the tranny this morning. No glitches so far. I was able to recover the retaining nut. When I removed the bit of shaft, it was about 3/4ths of an inch long.

My steady bearing is very loose and rumbly. How does it come away from the drive shaft? Are they similar to the one on a gasser?

I peered in at the pilot bearing and it is the bronze kind. Should I replace it with a needle bearing or a kevlar?

 

I assume you mean the center bearing on a 2 piece drive shaft? It should just slide off the driveshaft.

I would definitely replace the pilot bushing while you have things apart. I don't know if a needle bearing type is available.

 

I will change the pilot bearing. The steady bearing is very loosely held from coming off the drive shaft by a sheet metal flare. It looks like a press fit but I don't know for sure. There is a larger flare up against the main tube of the drive shaft. Perhaps I should just try to force the flare off by using the bearing. It is soaking in liquid wrench for now.

 

Great news. I took the mainshaft over to North American DriveTrain here in Edmonton and they looked at it. The gears are good. Third gear had already been upgraded. There were a few nearly worn out synchro's and some were only a little worn. They told me how to go about the teardown and how not to break the new synchro's. The best part was that the shaft, bearings, seals and synchro's (and tax) came to less than they phone quoted me for just the bearings and shaft.

I went to napa and got a new pilot shaft bearing for $2.75 C and a new drive shaft hanger for $40 complete.

The only thing I am short on right now is shims but the old ones may be more than enough. Heck, I even found a doo-hickey which fits my crawler-jack and holds the tranny at the right angle for re-insertion. $29

I understand that the preload on the mainshaft is about 4 to 6 thou.
Does anyone know what it is for the countershaft?


As of 2:15 local time I am still without a manual. A .pdf copy emailed to

billtomlinson@shaw.ca would be greatly appreciated.