Regear

[Jeepmedic46]

I just had my transmission rebuilt and the gentleman said I need to regear otherwise I’m going to burn the transmission out. It’s a 2000 Cherokee with the 4.0 and 3:55 gear ratio. Currently running 265/75/17 BFG Mud Terrains. Will I burn out my transmission?

 

[Anak]

That is a 31.7" diameter tire, according to Google.

I think there are lots of folks running 31s on 3.55 gears and having no issues.

The question would be, does that extra 0.7" become the straw that broke the camel's back.

I am fairly certain that by the time you get to 33s you really need to re-gear.

The location of the line separating the two probably also depends on your usage. You should probably share what sort of driving your rig has to deal with.

 

[RCP Phx]

Yes you are putting additional stress on the trans but a good trans cooler will take you a long way with helping reduce that!

 

[Jeepmedic46]

I’ll be putting in a good transmission cooler and temp gauge. Will have to figure out where to put that. Jeep does mostly driving around town and backroads to NH and Vermont for fishing. Doesn’t do a lot of highway.

 

[Anak]

Look for a "pillar pod". You can get them in dual or single gauge configurations.

 

[maxbraketorque]

I just had my transmission rebuilt and the gentleman said I need to regear otherwise I’m going to burn the transmission out. It’s a 2000 Cherokee with the 4.0 and 3:55 gear ratio. Currently running 265/75/17 BFG Mud Terrains. Will I burn out my transmission?

That's a 32" tire. With that tire size on stock gearing, 3rd gear is going to be pretty close to 4th gear on stock tires. You'll probably rarely be in a situation where it makes sense to be in 4th gear.

Anyhow, its gonna make the torque converter work harder when the torque converter is not locked, so the torque converter will make more heat, but a good trans cooler should help with temperature control. It you don't want to pay the big bucks to regear the diffs, then slap on a good size trans cooler, and drive in 3rd gear.

 

[Jeepmedic46]

That's a 32" tire. With that tire size on stock gearing, 3rd gear is going to be pretty close to 4th gear on stock tires. You'll probably rarely be in a situation where it makes sense to be in 4th gear.

Anyhow, its gonna make the torque converter work harder when the torque converter is not locked, so the torque converter will make more heat, but a good trans cooler should help with temperature control. It you don't want to pay the big bucks to regear the diffs, then slap on a good size trans cooler, and drive in 3rd gear.

I intend to regear my axles. Unfortunately I have to save to put the new gears in. Will put in a good trans cooler.

 

[wbnickens]

How many miles were the trans? It should be a AW4, which is a very strong.
When you go to 33s regear to 4.56 or 4.88.
I run 33x10.5 Toyo with 4.88 gears.

 

[Jeepmedic46]

How many miles were the trans? It should be a AW4, which is a very strong.
When you go to 33s regear to 4.56 or 4.88.
I run 33x10.5 Toyo with 4.88 gears.

The transmission had 286,000 miles on it. I would like to go to 33s but not sure they’ll fit. Would it be to much gear to put 4:56 with my present tires?

 

[xcm]

Your trans guy told you that you needed gears for basically a 31” tire?
I’d be finding a new trans guy…

 

[xcm]

The transmission had 286,000 miles on it. I would like to go to 33s but not sure they’ll fit. Would it be to much gear to put 4:56 with my present tires?

4.56 on 31’s isn’t too much, but it also ain’t the perfect ratio. It won’t hurt anything but you will loose top end MPH. The good thing is, is from a stand still, acceleration will be peppier. Unless you drive hundreds of miles a week, it’ll be fine semi temporarily.

 

[wbnickens]

Your trans guy told you that you needed gears for basically a 31” tire?
I’d be finding a new trans guy…

I agree!

 

[Jeepmedic46]

The tire is a 32” tire. I’ll put in 4:11 gears. 4:56 would be overkill.

 

[techno1154]

Your trans guy told you that you needed gears for basically a 31” tire?
I’d be finding a new trans guy…

When I changed tires from the original OEM size to 30" my XJ would gear hunt on every overpass when using cruise control. I regear to 4.11 and went up to 31" tires that are the JK OEM take offs. For 33 tires, I would definitely go 4:56 and not look back.

 

[xcm]

The tire is a 32” tire. I’ll put in 4:11 gears. 4:56 would be overkill.

4.56’s cost the same as 4.10’s, and labor is the same… unless you are 100% POSITIVE you will never go to bigger tires on those axles, go 4.56!

I install gears for a living. You wouldn’t believe how many people regear to 4.10, then a year or two later they are swapping out to 4.56/4.88. Do it once, do it right. Saving money is good!

 

[RCP Phx]

If you drive this on the street 4.10's, if it's a trail rig 4.56's!

 

[boncrshr]

How many miles were the trans? It should be a AW4, which is a very strong.
When you go to 33s regear to 4.56 or 4.88.
I run 33x10.5 Toyo with 4.88 gears.

I'm running 33s with 4.56 and wouldn't go with 4.88s if you do any highway driving at all. At 60 mph I am right at 2200 RPM. With stock tires and gears I was at or a hair under 2000. So yeah, it feels like I am flogging it at 70 mph.

 

[techno1154]

If you drive this on the street 4.10's, if it's a trail rig 4.56's!

Well stated.