Gear Ratios

[spacedust]

Hey I really appreciate the responses guys. I'm not positive what I have for gears but in guessing it's 2.35 unfortunately. I don't seem to have a diff tag, is the easiest way to tell by pulling the diff cover? Or is there a way to tell visually from the outside?

[EagleSX4_5Speed]

This should help there is a letter stamped into the rear axle on the right side of the diff cover that indicates ratio.



There should be a standard tag on the front axle but it will be very hard to see as the diff is very close to the front cross member.

[spacedust]

Thank you for the info 5speed! I don't use forums much but so far you guys have been awesome help. I'll check when I get home, funny that I just replaced the pinion seal and didn't even see the stamp.

[spacedust]

Well I have a 1982 disco with J stamp so I should be good to buy the same gear set from rock auto since mine should be 2.73:1. Woot!

[spacedust]

Are gear swaps doable for the average backyard wrencher? Did you guys get an install kit when you did yours?

[EagleSX4_5Speed]

I have regeared 4 different axles and it is doable. However I would get a quote from a local shop and if you can afford it have them do it. The first one I did took me about a week to get just right. Also don't try to regear it while the axle is still under the car. Do it on a workbench or with the axle removed from the car on some jack stands on the ground.

If you do it your self I defiantly recommend buying an install kit. I thought it would be cheaper to just buy the bearings I needed but ended up spending more to get everything I needed individually than what the kit cost.

[vangremlin]

I'm no expert mechanic but I would consider this job beyond my capabilities. Maybe watch a couple videos on YouTube a see if you would be comfortable doing this job.

Good luck!

[89 MJ]

I would say it's a little complicated for the average guy. It takes a lot of time and precise measurements (we're talking thousandths of an inch) and you need to have a hydraulic press as well. If you're comfortable with all of that, go for it.

[spacedust]

Thanks guys! Sounds like I should probably leave this one to the pros although ironically I have machining experience so I've got dial indicators and experience in the right tolerance department and actually have a hydraulic press too! I'll pull the diff even if I do bring it to a pro, it sounds like that's definitely the way to go. I found a couple of diffs in the junkyard, I might grab one since it's a 3.07 non disconnect. I assume the non disconnects can hold more power.

[89 MJ]

Thanks guys! Sounds like I should probably leave this one to the pros although ironically I have machining experience so I've got dial indicators and experience in the right tolerance department and actually have a hydraulic press too! I'll pull the diff even if I do bring it to a pro, it sounds like that's definitely the way to go. I found a couple of diffs in the junkyard, I might grab one since it's a 3.07 non disconnect. I assume the non disconnects can hold more power.

If this is a car that will see a lot of highway use, you might actually want 3.07s. It sounds like you could swap the gears though. Maybe watch a few videos on D30 gear swaps and see if it's something you think you can do.

[spacedust]

I watched a few videos and of course they made it look super easy, in realty I can tell that it takes some serious patience. I'm going to poke around and check to see what my local shops will charge.

Long term I actually am hoping to engine swap it. I was talking to a fella down the road that LS swapped his Eagle and I even found a Tahoe doner. His drove really nice and and his had 3.73 gears so I think 3.54 gears would work nice for me. It'll drive decent now with the inline 6 and if I do ever LS swap it then it will also be decent. Plus my 8.8 already has 3.55 gears that I don't want to change.

Are you guys happy with the gears you chose or would you do it differently now?

[89 MJ]

I went with 3.54 gears and for the most part am happy with it. Biggest problem is the fact that I am now turning too many rpms to spend any real time on the interstate because I don't have overdrive. If mine were a car that was going to stay with the factory 3 speed forever, I would wish I went with 3.07 gears. Because my car will probably end up with overdrive in the future, I am glad I went with the 3.54s. I also usually don't end up over 60mph.

[EagleSX4_5Speed]

I like the 3.54 gears in my car. However I do have the T5 manual transmission. It has overdrive and at 60 mph I am running 2200 rpm. At 80 which doesn't happen very often it is about 2900 rpm.

I found this gear ratio calculator that was very helpful in choosing the gears I did. You can compare what you have now with the new setup.

https://www.grimmjeeper.com/gears.html

[spacedust]

Do you guys daily drive your eagles?

[89 MJ]

Do you guys daily drive your eagles?

Sure do. About 120 miles per week.