HELP!...Torque tube bolts came loose...

[clifforddward]

OK Guys, what have I gotten myself into now....

Here is the situation...I was driving my late 31 around town yesterday at about 25mpg when all of a sudden I had a 'jolt" that felt like the parking brake grabbed...I glanced down and the parking brake handle was disengaged as it should be for driving....then it went away for about a half mile at which time the grabbing feeling came on much stronger...so much so that it stopped my car and I was locked up in the middle of the road. I rocked the car back and forth from reverse to 1st and back again several times...also got out of the car and rocked it back and forth...was finally able to get it rolling again at which time everything seemed OK again. I finished my errand run and drove about 3 miles (without further incident) back to my house where I parked and placed the car up on jack stands to fully evaluate the situation.

I had expected to see the parking brake lever springs behind the backing plate broken...actually what I found is there were no return springs in place on either side! (I have owned the car about a year and had not really noticed if there were return springs in place before this incident...I have driven the car 2k miles without any prior brake problems although I did adjust the brakes when I first got the car to even out braking action).

More worrisome than the missing parking brake springs was the fact that there was a torque tube to differential bolt hanging by its safety wire!...it appears the torque tube has loosened up from the differential...there appears to be a small gap now where the torque tube bolts up...the other bolts are in place with their wires, but the gasket has come out as can be seen in the photos.

For added information, there is a Mitchell O/D installed in the car...it was done by a northern CA club that has performed many of these installs, so I have no reason to believe there was any problem with the installation of the Mitchell.

Questions are:
1) Was the locking up likely due to the missing parking brake springs or somehow related to this loose bolt in the torque tube?
2) Can I reinstall the torque tube bolts and see if things are OK with the rear end by doing a test drive or what else is recommended.
3) Can I replace the missing parking brake return springs on the back side of the backing plate or do I need to pull everything off to do this?

BTW, before anybody mentions it, I do know that the differential housing has the wrong bolts holding on the two sides...I have a set of old original diff bolts to replace these modern bolt/lockwashers. The modern ones do allow the Diff housing to leak, but otherwise have remained tight.

Thank you in advance for any and all suggestions on what is the root cause of my problem and recommendations on next action.

[Bob C]

Well if the bolts are safety wired and they came loose then most likely they are stripped.

[Pete]

Assuming the Nor Cal Club did everything right on the OD installation, someone has worked on the car since then because people that know what they are doing do not leave parts out and use wrong bolts etc etc.

My suggestion is find someone that has a known good reputation with working on model A's and have him fix it.

[Gary WA]

At least all safe and auto in garage!! Look it over good and get it back on the road.!!

[jack backer]

If it’s the club I know up there they are a bunch of hacks.. some good mechanics in that club but they shy away from the ‘group’ jobs.. eight monkeys and one wrench.

[clifforddward]

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Originally Posted by Bob C

Well if the bolts are safety wired and they came loose then most likely they are stripped.

Crazy thing is the bolt hanging down does not appear stripped at all...after taking these photos I wiped it down and the threads appear fine...now does that mean the diff threads are stripped?...maybe...and I have no idea how that bolt could have vibrated its way out.

It will be the weekend before I can get into it...figure I'll cut away the wire and see if the bolts and/or diff where they screw in is stripped.

If the holes in the diff housing are stripped then of course I'll have a far bigger problem on my hands!

[Tom Endy]

The torque tube bolts should have been torqued to 35 ft. lbs. I suspect they were not. There should be no lock washers under the 20 banjo bolts.

The photos appear to show that you lost some oil out of the banjo. The loose torque tube bolts could have allowed things to move around inside the banjo and possibly have done some damage. That may have been the clunk you heard.

No telling what else was left loose inside. If it were mine, I would pull the rear end and overhaul the differential.

Tom Endy

[Brentwood Bob]

It won't go away. Wrong bolts?
Do not retap the housing. Your tap will probably not match the OEM bolts.

[Terry Burtz, Calif]

There should be no gasket between the torque tube and the banjo housing.

[rotorwrench]

Check and see if the bolt is whole or broken off. The axle assembly may have been damaged if the vehicle hit a big pot hole or some debris in the roadway. Also check the radius rods for signs of looseness or damage.

If a bolt gets loose or is not properly secured, it will start working in the hole. Over time, the threads in the bore and on the bolt will wear very quickly. I've seen this happen on certain helicopter drive system parts before. Several times I've found bolts dangling by safety wire over the years.

The mention of a flange gasket could explain a possible cause for the loosening but it would depend on the composition of it and how thick it was. Many times all that is needed on a structural flange is just a sealant. Modern anaerobic sealants are very suitable for this application.

[nkaminar]

At a minimum pull the rear drums off to see if there is any damage to the parking brakes. The parking brakes on a Model A can be damaged if used as emergency brakes or in your case if the were on while driving because of the springs missing.

Yes, you can add the springs, but they are difficult to install. Several owners have made special tools by grinding slots in screw drivers.

It is likely that the differential was not assembled correctly when the overdrive was installed. You will need to take the differential out of the car and disassemble it for inspection and repair.

[Planojc]

Just a thought, could the bolt have been left out to vent the banjo. I have seen several banjo's have venting problems due to the short torque tube on the Mitchell. I vented mine on the top of the axle housing.

[Will N]

A bolt that's safety wired can't back itself out. If I had to guess, I suspect the bolt was pushed out from the inside by some broken gear tooth, and now the threads for that bolt in the housing are stripped. Don't just bolt it back together. You have a pretty big task ahead of you to take the rear end all apart, inspect, and repair.

[redmodelt]

How would a gear tooth get past the 2 carrier bearings? But I agree, needs to be checked out.

[Model "A" Fords]

Could a piece be broken off from where the missing bolt threaded in and jamming inside the banjo housing?

[Y-Blockhead]

Originally Posted by Will N

If I had to guess, I suspect the bolt was pushed out from the inside by some broken gear tooth, and now the threads for that bolt in the housing are stripped.

Originally Posted by redmodelt

How would a gear tooth get past the 2 carrier bearings? But I agree, needs to be checked out.

That bolt hole is below the carrier bearings. All of the toequw tube bolts are outside of the carrier bearing diameter.

But I don't think that was the issue

[jack backer]

Perhaps I should be a little more diplomatic. Group member community repairs performed with donuts and coffee can lead to an oversight in a critical process.. ‘Harry installed the torque tube bolts and Louis lock wired them”. The odds of a mechanical failure causing this issue is low.

[Marshall V. Daut]

My guess is that the hole's threads are stripped or severely compromised. So, someone simply glued in the bolt, hoping that would stop any leakage, as well as trusting that the safety wire would keep it in place. As already suggested, however, internal pressure probably pushed the bolt out. Try threading a different torque tube bolt in the hole to see if the threads are stripped. If so, that solves the mystery. Another half-assed repair by a previous owner that YOU now have to resolve.
Marshall

[jack backer]

Drain the differential and do a metal check on the oil.. letting it spill across a white paper towel will catch any metal fragments. The worse case scenario is when the bolts were loose the pinion worked away from the ring gear, causing uneven tooth wear negating a proper backlash.