How to get in/lbs reading on gears?

cmozez said:

I'm having trouble finding a way to get reading on my pinion install. I need to read 8-14 in/lbs but the lowest torque wrench that I have found starts at 50. I don't want to go buy one just to use once and I have tried all the parts houses that have the tool borrow program. How did you guys obtain these readings?

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Try this . It sucks to spend the money, but if you are going to do it, do it the right way.

You could always buy it, use it, clean it up real good, and return it........ I didn't really just say that, did I???





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That's not really what you want. You are not really torquing anything down, to the point where you would make a torque wrench "click"
What you are doing is checking how much preload you have on the pinion bearing. You are crushing the crush collar, or sleeve if you will. You need what they call a dial type torque wrench. Go to ebay and search for "dial type torque wrench" if you want to see what they look like. You are really measuring the drag in in/lbs. Mine reads from 0-75 in/lbs. in 1 in/lbs. increments. That would really be the one you want if you were to buy one. It is made by Proto tools and is model #J6169F. Once you tighten the nut to the minimum torque in ft/lbs, which means you have started to crush the collar, then you put this on there and just turn the whole nut and pinion and everything to get a reading of how much drag you have. Then you go from there and give it a little at a time till you are where you want to be. Maybe you could borrow one from somebody you know who is a mechanic? If you got anymore questions about the job, fire away. Also that collar can be a real bitch to get started crushing. I've had to break out some super heavy duty setups before. Like a 3/4" drive breaker bar with a pipe on it and pushing it with my feet and legs from under the car. I have had luck before with just torquing it to the minimum ft/lbs. plus a little bit more and just making sure it has no play and is not so tight it wont turn. I've put 80,000 miles on one that I did that way with no problems. It's probably not quite as big of a deal as they make it sound, but it is nice to have the right tools and at least go through the motions of doing it right, if you can. My wrench cost me around $130.00 and I bought it through MSC industrial supplies. Grainger probably has them too. Good luck, Russ

Ah what the hey, here's a pic. It is 1/4" drive, so you definately have to do some stepping up to get the big socket you'll need. Just remember though, you are not torquing anything down or putting any kind of force on this setup. You are merely checking the drag associated with turning the pinion.

sounds like you need to find a friend to borrow a torque wrench from. as a last resort, measure preload with your hand. it should not be loose, yet it should not be tight. you should be able to rotate it with very little effort, but you should not really be able to spin it and it keeps on spinning. it should be very smooth. this is definatly not the recommended method and i can't tell you if it will effect bearing longevity, but it's worked for me before. you kind of get a feel for it once doing it a few times.

do you know anyone with a rearend laying around? if so, go give it a few turns to get a feel for it. remember how it feels. this comes in handy in the future too. next time you'll probably remember to take note to what it feels like before tearing it apart. cool?

ok here is the ghetto method.

buy a 1/4 inch drive inch/lb torque wrench from Harbor Freight. I think it was 19 bucks.

Weld a 1/4 inch drive deep socket (8 or 9mm) inside a 3/8 to 1/2 adaptor. Now you can adapt 1/4 inch to 1/2 inch to get onto that (I think 22mm pinion nut).

Before you tear down your original setup test the torque wrench break over point. Use slow consistent force and determin your starting point. If the original gear setup has miles on it, it tends to have less drag (say 8-15 in/lb). New setups with new pinion seals, new bearings etc. will be up to 19 in/lb. Once you've got your feel for the drag, setup your new gears. This is not an exact empirical method, but is a comparison method which is a hell of a lot better than guessing or just spinning it with your wrist and shot-gunning it.


I have done this on two gear setups. Maybe I'm just lucky?

Total investment about 25 bucks.

If you think that's ghetto you shold see my pinion depth tool!!!

When I order my tools at work through MSC it comes the very next day everytime. The harbor freight idea sounds good as far as being able to just go pick one up, as long as it is the dial type, or at the very least the bar type. If you are gonna be that pressed for time and don't really want to spend money, then don't. I couldn't get my nut to even pull the flange on the first time I did it. So I took the whole rearend out and took it to work and pressed it together in the hydraulic press till there was no more wobble. Then I just zipped the nut on there good and tight and called it good. Never had a problem with it. I just decided to get the wrench because it seems like I do it a lot now with other peoples cars and our Jeep etc.

I cut a piece of 1/8" plate to the rectangular shape of the u-joint companion flange, drilled holes in the corners to line up with the u-bolt holes and put a 1/4" square hole in the center to fit the torque wrench. When I have the big nut tightened, I put the plate on finger tight with some spare nuts and bolts and plug the torque wrench into it to check the rotating torque. (preload)
Howard

Park tools sells an inexpensive in-lb torque wrench for working on bicycles.Check out a good bike shop or there are places on the internet that sell them if you do a search.

a had a ford tech doa rear end for me once. He did backlash by hand and pinion bearing preload. Only thing he measured was pinion depth. "theyre just big meat grinders" haha, Its still holdin up with 10 k on it

I am in the midst of an 8.8 setup.

This is really country boy, but....

I just installed the new pinion. It would not read on my Craftsman 25 in lb and up clicker torque wrench, so I put a 9 in breaker bar and a fish scale on it, vertcally so the weight did not affect it, and still came out with less than one lb force at nine inches or about 9 in lb. This was only for pinion depth mockup. I have not attempted to do the crush collar yet so it appears to be working.