Torque Tube Question

J

jhowes

Well-known member
I have been rebuilding my rear end ( the cars). As I follow the Tom Endy tutorial I am not able to remove the bearing seal and bearing sleeve. Then I noticed that these parts are not mentioned in the Les Andrews book as far as removable is concerned. The question; is it necessary to remove them for a rebuild of the rear end and torque tube? These are Snyders part numbers A-4655 and A-4245. Jack
 
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The A-4245 seal is probably shot. Most are never replaced during an overhaul. If you are using my 2014 document, page 3 tells you how to remove both the seal and the sleeve. They have to come out together. Page 50 something tells you how to install the new seal and the sleeve.


If you don't have the 2014 document go to www.santaanitaas.org and click on my name. Scroll to the differential section.


Tom Endy
 
Re: Torque Tube Question - need advice


Hello Tom
First of all let me sayhow much I appreciated your article on rebuilding of the rear end, andespecially all the great photos. I had not seen this article before.
About ten years ago Ipurchased a used Volvo bell housing, transmission and overdrive set. I then disassembledthe unit and cut the Volvo driveshaft to separate the OD from the ******. I thencut and splined the Volvo OD shaft as well as cut the Mdl.A drive shaft andtorque tube. I cut and splined the A driveshaft coming out of the differentialto form a stub shaft. This was to connect the OD into the drive train. The cuttorque tube was welded, both front and rear, to the OD framework. The sleeve,bearing and grease seal at the front of the torque tube was left as original. Althoughthere was barely enough room on my 1930 deluxe roadster to squeeze it in, I wasable to tack the drive gear to the rear stub shaft and relocate the speedometerto accurately measure actual output ground speed. I also rebuilt the rear endat this time.
This "shade-tree"mechanic, with not much more than basic tools was totally shocked on the firsttest run. It ran to perfection without a hint of vibration and shifted into andout of OD as smooth as could be. Tenyears later, I have not had one bit of trouble with it and I am still totallyin love with it.
However, even with thehelp of all my very much appreciated and invaluable contacts and my research onthe internet, there is one item that I apparently overlooked. I havedisconnected several model A torque tubes in the past and had never seen greaseor oil in the torque tube on the rear end side of the bearing and seal assembly.I seem to have assumed that all the oil in the differential stayed in thedifferential banjo, and if there was to be a leak, it would be out through theaxle assemblies.
In fact there isconsiderable oil leakage past the two pinion bearings into the shortened torquetube which now terminates at the rear of the OD. This torque tube section hasno seal and I had to mount a small collection basin at the OD end.
I cannot understand whythis assembly is leaking so much #400 oil. I am surprised that there was noprovision for a seal here. I don't know how I could install a seal in thetorque tube at the rear of the OD.
All comments very much appreciated.
Thank you,
George


 
The three seals used in the Model A rear axle assembly, one at each end of the axle housings, and one at the front of the torque tube are all the same part number and they are grease seals, not oil seals. Many in the Model A hobby insist they are oil seals, there for the purpose of keeping differential oil in the banjo from migrating out to the brakes and up to the U-joint, They are not there for that purpose.


The purpose of the grease seals in the axle housings is to direct grease that is pumped in through the grease fitting on the end of the axle housing to the rear wheel bearings. Without the seal the grease does not go to the wheel bearing, but travels down the axle shaft toward the differential.


The grease seal at the front of the torque tube is there to prevent grease that is pumped in through the grease fitting on the transmission rear bearing retainer from going past the U-joint and drive shaft roller bearing and traveling down the drive shaft.


Most cottage industry Borg Warner and Volvo overdrive modifications used the same grease seal as used in the Model A rear axle assembly as an oil seal on the stub shaft, which is also not a machined surface. The grease seal does not do a good job of preventing oil from the overdrive from migrating into the differential.


As the oil level in the differential rises it could migrate out to the brakes and the grease seal there will not prevent it from getting to the brakes.


Anyone still running these overdrives should check the oil level in both the overdrive and the differential about every 400 miles. remove oil from the differential and add oil to the overdrive.


Tom Endy
 
Tom, Thank you for your prompt reply.
The OD has run perfectly and has not lost a drop of oil in 10 years.
Oil is leaking past the pinion gears into the torque tube. This creates a bit of a mess and requires adding oil to the banjo at frequent intervals. There was no oil leak here before I did the OD conversion and I am wondering if I did something wrong on reassembly. I installed new bearings on reassembly.
If I erred on preloading the pinion would that cause the leak?
Any thoughts would be appreciated.
Thank you.
George
 
I reread Geo.T's question a couple of time and am now not sure where it is leaking? Normally there is a passage that allows any lube that has worked past the pinion bearings into the tube from the rear end to flow back into the housing. If it is leaking at the joint, could be loose or? What lube are you using in the rear end? I don't see how preload on the pinion or carrier bearings would be the problem. Might be loose parts or bad gaskets.
 
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