rear gear install question

[stprorolla49]

my buddy dave used to work at a few ford dealers, and has done rear end gears before so thats not the issue.....he's got a set of 3.73's in his 93 LX hatch rite now, and is switching to 3.90's so he said he'd sell me teh 3.73's fir CHEAP if they are in good shape....my question is, is it difficult to set up the crush sleeve, and shims and stuff without having use of a lift?? we can get eh car about 2-3 feet in the air on cinder blocks, and multiple jacks......will this be enuff?? if i can get away with $75 for gears and no charge to install em except for a couple or burgers and a few cold ones, i'd be stoked.....thanks guys!!!!

 

[94-302-vert]

A guy I work with tried to do that but he couldn't get enough leverage to crush the crush collar.

On my car the installer did not crush the crush collar enough (pinion had less than 2-3 in-oz rotational torque on it with new bearings) and we were able to do that on jackstands (don't use cinderblocks, jackstands are cheap)....

What you need is a bar with holes drilled in it so you can bolt it to the driveshaft flange on the differential, preferably so it contacts the ground or the car to keep it from spinning. Also I read on here that someone realized that if you reach in through the passenger side wheel well you can easily generate enough pulling force to torque it up.

So yeah it can be done, especially with more than one guy. Hindsight, I wish I had installed mine myself in the beginning...

 

[stprorolla49]

A guy I work with tried to do that but he couldn't get enough leverage to crush the crush collar.

On my car the installer did not crush the crush collar enough (pinion had less than 2-3 in-oz rotational torque on it with new bearings) and we were able to do that on jackstands (don't use cinderblocks, jackstands are cheap)....

What you need is a bar with holes drilled in it so you can bolt it to the driveshaft flange on the differential, preferably so it contacts the ground or the car to keep it from spinning. Also I read on here that someone realized that if you reach in through the passenger side wheel well you can easily generate enough pulling force to torque it up.

So yeah it can be done, especially with more than one guy. Hindsight, I wish I had installed mine myself in the beginning...

thanks a lot bud....i hear what your saying about the jackstands cause ive got like 8 of em, but when i jack my car up, i like it to be really stable, so i jack up teh front end by the k-member, and put a cinder block or 2, and a few pieces of 2x8 wood under the a-arms, then i lower it down, and keep the jack just touching teh k-member for support......in teh back, i just use like 4 jackstands and a floor jack cause i need the working space

these are some great tips, and i think were going to have at it....theres a company that he mentioned to me last nite (i forget teh name at the moment) that makes a spacer that takes the place of the crush collar, so you dont have to crush anything, making it a bit easier....i'll find out teh name tonite and check back later.....

anyone else got any helpful tips???

 

[R.J.]

I don't use crush collars anymore, I use a solid pinion spacer and shims. You just TQ it to 125ftlbs and check break away TQ on the pinion, then adust shimming from there. It is alot stronger to.

 

[mo_dingo]

There is a nice little trick to tightening the pinion nut to collapse the crush collar.

Remove your driveshaft and make a template of the pinion flange and where the bolt holes are. There are more holes in the flange, but only 4 are threaded for the driveshaft.

So with the template, take a piece of thick steel plate, like 1/4in. thick, and cut out the template, and drill the holes in it for the bolts and a big one in the center that's bigger than the pinion nut .

Then take some flat stock, cut it to 3ft long and weld it to the template. Now you have a way of bracing the pinion flange while you turn the torque wrench. Just use the driveshaft bolts and bolt up the tool and torque it down. And actually the trick way to do it is while you are pulling on the torque wrench, you push on the tool, and it doubles your leverage. So now you only have to push to appx. 60ft.lbs instead of 120.

Or you can do like I did, and in the same manner, use a huge prybar and install the bolts but don't tighten them all the way, and use that as a lever.

The next time I have to remove my pinion I will definately make the tool.
Scott

 

[Mac-man]

we just normally use an impact gun to get it to start taking up the slack. the hard part in crushing the sleeve is the initial collapse of it, once it starts to get crushed it is easier to do, so we used an impact gun on mine to do it and then used a torque wrench the rest of the way.

 

[stprorolla49]

thanks for the info guys...i think ima try and tackle this job sometime over the winter.....i trust my buddy to help me, cause he knows what hes doin, and i dont have $300 bux or so for the install.....anyone have a step by step write-up for this???

 

[GRGT1994]

Good suggestions above. Here's what I did to get the crush collar crushed: I reached in from the passenger rear wheel well, and pulled on a breaker bar length ratchet. If you get it up in the air far enough (on jackstands please), then it is not so tough. Actually, I worked on it with a friend, with one under the car just to pull the ratchet back and reload it for each 1/4 turn, as well as to check the preload. Then the other guy could just stay put and focus on pulling on the ratchet.

BTW, if you don't already have a breaker bar length 1/2" drive ratchet, now would be an excellent time to get one. It will be far easier to use than a breaker bar, and I can't imagine doing it with a smaller ratchet.

Good luck, and enjoy the soothingly pleasant aroma of friction modifier!

 

[larrendeuce]

I also used an impact gun. I put the largest screwdriver I had through one of the bolt holes and braced it against the housing. My cheap old impact gun was too weak and did nothing . I bought a 710 ft lb gun and that worked fine. I had nothing that was hardened to use in place of the screwdriver.

Disclaimer: Most don't realize that regular sockets and non-hardened tools can explode when used with impact tools. Always use impact sockets, prybars, and chisels for the proper application and not substitute screwdrivers and chrome sockets if you value your sight.

 

[larrendeuce]

Good luck, and enjoy the soothingly pleasant aroma of friction modifier!

I know that smell! When I picked it up the whole interior of my lightning smelled like it. Then I went to use it and noticed it has an intact foil seal. Wow is that stuff strong.

 

[stprorolla49]

thanks guys....ow long do you think it will take me and my buddy to take out the old gears, and put in the new ones???

 

[GRGT1994]

how long do you think it will take me and my buddy to take out the old gears, and put in the new ones???

I you are not doing the trac loc, just the gears, then maybe you can get it done in a day, possibly less if you or your buddy have experience and work efficiently.

I did the trac loc too, so I just planned on one day to tear down, and another to rebuild. But then again, gear were my first mod, so I was really green and took lots longer than those of you who know more about working on cars.

Remember, you will need to pull and press the pinion bearing (to get the shim off too). And that might mean a trip to a shop. So figure in some road and down time too.

 

[stprorolla49]

I you are not doing the trac loc, just the gears, then maybe you can get it done in a day, possibly less if you or your buddy have experience and work efficiently.

I did the trac loc too, so I just planned on one day to tear down, and another to rebuild. But then again, gear were my first mod, so I was really green and took lots longer than those of you who know more about working on cars.

Remember, you will need to pull and press the pinion bearing (to get the shim off too). And that might mean a trip to a shop. So figure in some road and down time too.

yea my buddy has had 13 mustangs in the course of about 5-6 years, and most of them have been insane......its safe to say he knows his ****.....i also have a press that i could use for the bearings...my uncle and my dad split the funds for a lot of bigger, more expensive tools, that they both only use occasionally, and since we live about 5 minutes away, i dont think it will be an issue using his press......thanks a lot guys.....any more tips would be great, and does anyone know where there's a step by step writeup??

 

[94-302-vert]

here is a good overall Tech link: http://www.mycoolmustang.homestead.com/techarticles.html

Here are a couple good links off this page for the gear installs:
http://www.corral.net/tech/drivetrain/gears.html
http://home.flash.net/~ivc1/cobra/solgear.html (preferred)

 

[GRGT1994]

Search mo dingo's posts too. He has posted lots of good stuff on gear installs.

Make sure you have the fitting to pull the abs sensors. I think that screw is a reverse torx.

Oh ya, plan on the abs sensors being permenantly rusted in, and needing to smash them out.

 

[R.J.]

This write up is specific to the shiming of the pinion and carrier. I have this saved to a folder and a printed copy. It is very specific info and includes all the math and examples. Again this has no actual remove or install steps for the job but is a big step in the job. My shims came out perfrect using this procedure.

Determining proper pinion depth isn’t difficult if you know how to do the math. That’s exactly what we’re going to show you, using our 8.8 Ford axle as an example. Get a calculator and follow along.
Step One
Find the diameter of the differential side bearing race (dial calipers are great for this). Ours
measured 3.063 inches. Divide this number in half to find the bearing race diameter:
3.063" ÷ 2 = 1.531"
Step Two
Measure the distance between the main bearing cap mounting surface and bearing bore as in Photo 13. Since we are working with a 1.531 inch bearing race diameter, we used a two inch extension on the Tavia pinion setting tool to get a complete reading (the indicator needle will depress a half-inch, putting us right on the money). Our indicator read .465 inch.  Step Three
Subtract the bearing bore reading from the length
of the pinion tool extension. This is the actual axle centerline. The equation for our 8.8’s centerline is:
2.000" – .465" = 1.535"
Step Four
Next, subtract the bearing race diameter from Step One from the axle centerline. This is the amount the axle housing is off-center. Our axle was off-center by .004 inch, as shown:
1.535" – 1.531" = .004"
Step Five
Now you need to measure the distance from the axle
housing centerline to the face of the pinion gear. Install the pinion gear as shown in Photo 14. Since the pinion depth marked on our Superior pinion gear is 2.552 inches, we used a three inch extension on the pinion setting tool. Measure the distance  between the pinion face and the axle centerline. In our case, the measurement was .416 inch.
Step Six
Subtract the reading from Step Five from the length of the pinion tool extension, as shown in our example:
3.000" – .416" = 2.584"
Next, subtract the off-center figure from Step Four from your answer. This will give you the actual pinion depth:
2.584" – .004" = 2.580"
Step Seven
To find out how much you need to shim the pinion gear, subtract the depth marked on the pinion gear from the actual pinion depth you just found:
2.580" – 2.552" = .028"
Thus, we need a .028 inch pinion shim pack.
See, that wasn’t so bad!

 

[Grn92LX]

Buy NEW gears, not used.

 

[mo_dingo]

thanks for the info guys...i think ima try and tackle this job sometime over the winter.....i trust my buddy to help me, cause he knows what hes doin, and i dont have $300 bux or so for the install.....anyone have a step by step write-up for this???

Check my sig. I basically followed the install writeups, and made notes to anything that I found out of the ordinary, what workes well, etc...

The #1 thing I can tell you is that make sure you are prepared. Otherwise you will be making TONS of trips to the parts store or wherever.

In my sig, I made a parts list document. You need to review it and make sure you have everything listed. It took me a month to accumulate, seriously. It basically lists everything you will need.

If I didn't list a carrier shim set, then you will need that. I didn't list it because i didn't need it, and I don't think anyone will. As long as you got FMS 3.73's, the backlash readings should be within spec, and changing out the huge shim on each side won't be necessary.

Read over the install article 10 times. Then read over mine 10 times. i did, and it helped me really get a grip on something that I have never worked on in my life.

After all that research, I got my car on a lift, and 3.5 hours later I had my gears on and I was cleaning up and lowering the lift. Seriously. I did have a helper, which is mandatory. But he wasn't helpful in the knowledge department.

When you are ready to install you gears, PM me and I can give you some tips. If the gears are FMS, you will be in for a shocker. It's so incredibly easy. It's just a matter of understanding what's going on, and why.
Scott

 

[GRGT1994]

Buy NEW gears, not used.

Agreed 1,000 times over!!! I forgot to mention this above, but for god's sake buy some new gears.

This is not an area you want to cheap out on, given all the increased opportunities for gear whine with used gears (regardless their condition). And you're only talking about spending less than $200 for Ford Racing gears.