torquing a pinion nut

[old cool]

Now here's a topic that has multiple threads going back years and years. That's why I'm bring it back to the surface. Like many who have brought this to the forum, I have a leak at the pinion seal; and, I have a vibration between 15 and 35 mph. I have been told by a shade tree mechanic that it is not my u-joints.

I have read almost every thread I could (over an hour) and I'm confused. Yesterday, while visiting my local NAPA store, a good guy behind the desk said to drop the drive shaft and tighten the pinion nut. That's it (meaning that could be the problem; not ruling out other problems).

There were only a few threads that made it sound that simple. One member said the crush sleeve was already addressed at about 300 ft/lbs and therefore to tighten the pinion nut at 125 ft/lbs wouldn't matter (if it's too loose). Some threads sounded similar; adding that locktite should be used and a new pinion nut. All other threads were addressing potential problems with over tightening the nut. Some disagreed and said you can't over tighten with a 1/2 torque wrench.

I hope I can get a consensus without getting even more confused.
NOTE: I have seen you tubes where a mechanic marked everything up to reset and align after putting a new seal in. He then turned the pinion nut a little beyond the mark because he said he could feel looseness. That being said, is the NAPA guy right?

I have a Dana 44-1, 354 in a 1966 GMC

[66Submarine]

You need to torque the pinion nut until the bearing preload is where you want it; no telling what's up with the crush sleeve, and if it ends up tight you'll smoke the bearings and lock everything up. Since yours was supposedly rebuilt (IIRC), the crush sleeve may not have ever been torqued down correctly, leaving the pinion bearing loose (and the nut tight).

I can't speak for the guys in the threads, but I can put a LOT of torque on something with a 1/2" breaker bar; God forbid using a pipe over the handle for more leverage. If you put 200lbs on the end of a 2' bar you have 400ftlbs, so yeah...

You need to torque the crush sleeve down until the bearing preload is correct, since that's the way it's set. If it was my truck, I'd take the rear end apart and replace the seal and set everything up again.

[old cool]

Would you agree that I could tighten the pinion nut as long as I kept within 125 ft lbs? I have a torque wrench. Going back to my confusion, there are two clearly different opinions out there and on this forum (see thread 202862, MikeB) . and the guy at napa was an older guy; seemed withit.

[Wrenchbender Ret]

The guy on U-Tube makes more sense then the Napa guy. If you cant feel any looseness in the pinion brgs. & the rear end has no whining noise I would mark everything, replace the seal & put the nut back where it was. Use locktight on the threads.

[66Submarine]

Originally Posted by Wrenchbender Ret

The guy on U-Tube makes more sense then the Napa guy. If you cant feel any looseness in the pinion brgs. & the rear end has no whining noise I would mark everything, replace the seal & put the nut back where it was. Use locktight on the threads.

The rear end is howling. I'm betting the guy never set the preload correctly and the pinion bearing is loose (or something like that). I think he said the guy had just "rebuilt" it or something; you know how that is...

[old cool]

since I'll probably have the have it repaired anyway, I thought it would be worth a try because that's about as far as i want to take. It does make some noise and there is vibration between 15 and 35 mph. Thanks for response.

[old cool]

Yep Sub. The po said he looked at gears and all looked good so he buttoned it back up. There wasn't a drop under the truck for the first week. Im thinking like you. He either got into it beyond his skills or he tightened the nut just enough to stop leak and it loosened back up. Oh yea, my very first thread was drive line noise. Think this rear end mess is the culprit. Wish I could fix it myself. Paid good $ for this truck. I may have made a mistake.

[jtrichard]

put a new seal in it and set the load as per the book it is better to be a LITTLE on the tight side than loose.... it is leaking 1 because its is old 2 because it is loose from many miles or both when you tighten the pinion it will set the crush sleeve to the wear that has occurred over the years/miles

[old cool]

my continued thanks everyone. Of course I failed to mention that the seal was changed about 500 miles ago by the previous owner. so I am back to the same question, basically, should I change the nut and just tighten. Or should I just tighten? If I use a breaker or torque wrench I know I can't hit the big #s.

[Oldtruckfanatic]

Honestly I know this sucks but if its making noise and its loose it wont stop making noise once its tight. The vibration might stop but once a wear pattern is established it takes very little time to do damage that will cause it to make noise thereafter. If I have a customer car making rear end noise I dont risk their safety tightening it back up or trying to reshim or reset pinion depth. I buy a ring and pinion set and an install kit and start over. Noise is friction and friction is heat and abnormal wear. There is a lot riding on that rear end being built correctly including safety at highway speed. This is just one guys opinion for sure but if you can afford the peace of mind have a driveline and gear place fix it right and never worry about it again.

[jtrichard]

just tighten it up .... I agree once they start to whine/howl they never stop BUT I have had rears that have howled for years after they where loose or ran low on oil

[Joe Pass]

All the Dana 44's I have rebuilt had pinion shims, no crush sleeves....I'm pretty sure your 44 would be the same. Once you replace the pinion seal the pinion nut is torqued to the factory specs and the pinion preload dose not change because you can't make it any tighter than the shims allow. Shims are used during rebuild to set the desired preload 20inch lb rotational drag measurement is what i use. Its more work to set up when rebuilding compared to a crush sleeve type differential. later when a pinion seal needs replacing there is no guess work preloading the drag with the pinion nut. Most Dana rearends are these type of setups.

Keep in mind if the rearend pinion bearings are loose many things can be happening like bearing failure causing pinion gear misalignment and leaks. Some times oil leaks thru the pinion gear and yoke if sealant isn't applied during assembly and will leak at the seal location around the pinion nut. Axle bearings will fail and also be noisy so it would pay to seek some professional help trouble shooting it so you can make an informed decision whether to repair it or rebuild it...
I would suggest a reputable off road shop that does Jeep differentials since they use Dana 44's and would be more familiar with them...good luck
Joe

[padresag]

there is a reason the pinion nut is supposedly loose and it more than likely isn't from the nut backing off. something has worn and that has made the clearance. if the gears looked ok then you have a brg gone. seals do not cause vibrations, bad bearings cause vibrations. you more than likely need to pull it apart and see what it needs. by sounds of the yoke is also worn where the seal runs on it.
there is only one way to really fix it.
ron

[old cool]

So here's a summary of everything I've read to date; including old threads:

1.)It can't mess it up by tightening the nut cuz it's shimmed, and shims don't move. Also, the original settings exceed what I would probably be capable of setting (tightening) so therefore, tighten and maybe go a bit further. Now if the bearings or gears are damaged or worn, I can expect the noise will still be there. But, I can drive it for a long time; no problem other than noise.

2.)It's probably worn, improperly set, outa whack (could be R&P, could be bearings) and I need to tear into it to find out problem cuz it's not going to be solved by tightening the nut. And, it might be unsafe. It sounds like tightening will only put a "band aid" on the total problem. It may remove the vibration but there will still be friction and noise which is failure waiting to happen.

LOL: is everyone else receiving the same two messages?

NEXT STEP: I am happy to experiment with tightening so long as I can't damage anything. I won't take a pipe wrench and I will be under the truck so I'm not even going to get a full body torque. It sounds like I can gain some time and I have nothing to lose. Though I will hear noise. I've learned to deal with some drive line noise but I cant deal with vibration which feels unsafe and annoying; especially since my driving is usually in the range where the vibration is happening. BELIEVE me I am not a gambler and I really want to take it to the shop and be done. But, like most of us, I need 100's of $ for other stuff and I'm juggling to fix most important things first. I can't imagine getting bearings, ring, pinion, etc installed under $600, probably $900. Again, what have I got to lose? I should probably tighten it just to get it to the shop safely.

If I missed something, or I've misread something, please write. THANKS

[Oldtruckfanatic]

Im sorry my point was that proper diagnosis of the problem is the key to deciding if its safe of if it is goingto have a larger failure. You can certainly tighten it up if its loose and try it. The problem with noise is that its sometimes hard to determine where its coming from so while I too have seen rear ends last years making ring and pinion noise its not always easy to tell if theres a bearing failure going on that can lead to bigger problems. Unfortunately it requires some disassembly to diagnose properly. You can tigten it up without doing any damage and try it. You can also replace the seal and then tighten it up. I guess I just didnt explain very well that depending on what noise its making and how it sounds putting into gear it could have a bigger problem that may be worth having checked out. All you can do is try it and see. Sometimes its just better to bite the bullet and get it fixed than fight with it. When theyre already howling its harder to hear anything else going wrong.

[61K10]

the seal could be leaking around the outer edge, not the seal itself. sounds like you don't know if the pinion nut is loose. about the drive shaft, one piece or two piece? if 2 piece could be out of phase. I bought a tk that just had all u-joints replaced and it had the same vibration as yours around 15-30mph. 2 piece d/s was put back together wrong.

[old cool]

There is nothing better than proper diagnosis and repair. I was merely pursuing a means to try something free and buy some time.
Can I tighten nut without raising truck in rear? Can I turn the nut down till I can't turn it any more?

[old cool]

61 - its a 1966, 2 wheel drive, one piece, backing up a 250 six with 3 speed manual. have vibration thats gotten worst in past couple drives and forgot to mention, can hear rotation noise while driving along curbs and buildings. Like I mentioned above, old timer, shade tree racer, said it wasnt u joints. But???

[jtrichard]

My bad someone had mentioned a crush sleeve I did not see yours is a 44 if the nut is lose then you should replace or at least use Loctite and tighten it back up.. if the pinion is lose they you have bearing wear or bad set up I would pull it down and replace all the bearings JUST don't lose or move any of the shimming and your set up should be fine assuming it was correct last time it was setup

[66Submarine]

Yeah I missed that, too. AFAIK only a few late model D44's used the crush sleeve*; yours should have shims. It's the Chevrolet rears that used the crush sleeves.

*And I think those were front axles for 4x4 stuff, anyway.

[grs]

The drive shaft could be out of balance.

[61K10]

tighten the nut if loose and see if anything changes--

[padresag]

any bets on how long it will take the bull gear to jump the heifer gear?
ron

[old cool]

too funny! I'd still appreciate an answer regarding raising the truck before tightening the nut .or any tips.

[61K10]

you don't need to raise the tk if you can get under it. I would probably get stuck lol. If you raise it please use jack stands.