Ring and Pinions

[1972GMCsierra4x4]

You may have read my previous thread titled gear ratios, and I have one more question. I found a set of 3.73 gears that would fit my differentials but the problem is that they are in half ton axles. The differential numbers match up (DANA 44 fronts on both trucks and DANA 60 in both rear ends) I just need to know whether or not I can pull the gears out of the half ton axles and then mount them right up in my original three quarter ton axles.

[1972GMCsierra4x4]

Also, the axles with the higher gears are on a 73 instead of a 72 like my truck. I don't know if that makes a difference or not

[Ol Blue K20]

Half tons didn't run dana 60 in the rear, 3/4s usually had an eaton, so on the rear no, I'm not sure if the axle splines are the same on the frt 44s

[LONGHAIR]

If you have found a Dana rear end in a half ton truck, it's a 44 not a 60.
If it really is a 60, it's not a half ton axle.

Either way, I always recommend against installing used gears. It is just not worth the risk. New gears are not that much money, it's the labor that will cost you.....but it is worth it. Pay the pro, get the warranty, sleep well.

Most pros won't install used gears anyway.....and if they do, likely will not warranty them.

[Mike C]

There were some half ton Dana 60's. Mostly 67-68 big block trucks. They were a 6 lug semi-float design. But it would not have been original in a '73 and up. That would have been a 12 bolt until earlier 80's.

My own opinion about changing gear sets into different housings, is if you have to ask, you probably shouldn't. It's not rocket science, but it does require several tools most DIY'ers don't have as well as a little experience.

If you are willing to read, learn, and spend some then go for it. But Google is much more useful than asking this to a message board IMO.

[1972GMCsierra4x4]

so does anyone know the place to get gears for the front and back for the best price?

[Mike C]

I deal with Randy's Ring and Pinion, but the best deal on the gears isn't going to be the big issue. It's going to be labor. Most places get about $300 per end these days. It's about a 4 hour job per at $75 hour shop time. You also need install kit with bearings for each end. Total cost about $1100 by the time you get it done.

Usually cheaper and easier to find a set of used axles with gear ratio you want. Unless you have specific locker/limited slip in mind.

I'd consider finding a '73 and up 3/4 ton truck and getting the axles from it. I didn't see your other post so I am assuming you have 4.57 gears and want something more highway friendly? Mid 80's 3/4 ton Suburbans have 8 lug axles and most of them have 3.73 gears. Most are a semi-float 14 bolt after '81 though.

[1972GMCsierra4x4]

Yeah, I do have 4.57 gears and I would go with a different set of axles, but I really want to keep my axles original. The reason being that in the mid to later 70s GM changed the geometry of the front axle, maybe enough to where I'd need a lift for it to fit. Plus the original DANA differentials I've got now are good, heavy duty diffs

[1972GMCsierra4x4]

What exactly is the problem with using used gears. I don't see the difference in installing used gears vs used axles. Obviously the used gears would have a little wear on them but so do used axles

[1972GMCsierra4x4]

Im not trying to sound like an arrogant idiot, this is just the first truck Ive really worked on and I need some answers

[SS Tim]

The gears wear match. When you change housings or carriers the relationship changes. This changes the load path where the gears contact. So now they are wearing in a new spot and as a result can create a very high spot load until they wear in, if they don't howl you out of the truck or break first. It is very difficult to get used gears to track in the same pattern as the were running. If you must reuse gears then they should be pattern tested before anything is disturbed to document you are not moving a problem and to try and match the new setup to the old. Simply using the same lash and endplay (if you even can) does not make it the same. A used gear set hanging on the wall should just stay there.

[SS Tim]

Also need to check and see what the ratio ranges are for the carriers you are thinking of reusing. IIRC the Spicer/Dana 60 split point is 4.10 down and 4.56 up.

[SS Tim]

If you are not familiar with how all this works you might want to take a look at factory overhaul manual.
http://67-72chevytrucks.com/vboard/s...d.php?t=558016

Look at the cross sections and the entire gear setting proceedure. To answer an earlier question an axle simply slides into the differential side gear splines. While this also wears in to some extent it has nowhere the velocity or motion of a gear set.

[Rufton]

I've installed 3 sets of used ring and pinions. They all run quite and have normal temperature. The non-hunting ratio set did produce some glitter so I pulled it for inspection and cleaning. No way to verify historical timing of non-hunting gear. Found no issue. Produced no more glitter in second batch of fresh gear oil. Two sets were F_rd so they may not count but one was dana 44 from front diff of 4WD that I installed in rear axle.

[Bigdav160]

Just to pile on....

Back in the day when I was a GM tech, the local (big volume) driveline shop would buy every used gearset we would bring him.

Always nice to have a few hundred dollars extra in our pockets.