Towing with 4.11 and stock wheels

Considering of making a camper/tow rig of one of my XJs. I will be permanently loaded with camping gear and spare parts + towing 4000lbs trailer (another XJ).

the tow rig is 89 4.0 renix with AW-4, about 200k miles. I do not want to lift it nor put any bigger wheels than stock 225/75/15. I know that XJs with tow package came with 3.73 gears. The rig has now 3.55, I have one set of 4.11 axles I would like to put on it (30 and 8.25). Do you think the performance is going to be ok? Wouldn´t it be too low for stock wheels? If I would have to go for 3.73 I will have to buy new gears and have them set as they are very very rare here ...

Thanks for any input.

btw: we have quite a lot of hills in here, not a flat land at all

Performance will be excellent with 4.10's and a stock size tire. Can't say the same for MPG's though.

*That is a considerable amount of weight for a 200k+ mi transmission to be towing. Better have a good cooler.*

Personally I dont think 3.73`s are low enough for what your doin, 4.11 sounds much better.

we have speed limits with trailer at 50 mph, so I hope the 4,10 will be fine

in my opinion, 4:11's will be great for what you want to do. a friend of mine has a 90 Cherokee with 3:73's and it turns about 2200 rpm at 55-60, so 4:11's should be great for your purpose and it won't over rev the motor. hope this helps, :eeks1:

I'd be less concerned about go, and much more concerned with stop.

a 4K pound trailer and camping gear loaded in an XJ will be stupid scary, espacially with the renix era single diaphraghm booster. I hope that upgraded brakes are on your list as well.

A tranny cooler and trailer brakes are a must!

I've towed a 4k lb camper with my '96 w/ 3.07s (5spd). I think the 4.10s will be fine. You will also want a break controller for your camper.

get some good brakes and dual diaphragm booster.

thanks, the Chrysler I want to put in already has disks, and the trailer has brakes, but anyway I will swap the booster for a newer one version

Personally I think an XJ is a pretty poor choice for a tow rig, but that aside, I think 4.10s will be to low. You should be towing that amount of weight in third gear, not overdrive. Do the math for 4.10s with 28" tires and no overdrive. I dont have the chart in front of me but Im pretty sure that puts you well over 3000 RPMs at 60MPH.

EDIT:
I just ran it through a chart. I was off a little, At 60MPH you would be turning right at 3000 RPMs. Still seems a little high but your power would be good.

I tow a 3k bass boat with my 90 and 96 and both have 4.10 gearing on 30's. I think the XJ should have came that way. It will pull fine, but will still get a little asthmatic on long hills and the issue is when it kicks back into 2 it will rev way up! I never tow over 55 on the highway even on open flat road.

As far as rpm, in 3 I'm turning 2900 at 55, in OD its around 2300 at 60(not towing). No significant difference in mileage on the highway if you keep it under 65, around town I saw an improvement in mileage and lock-up occurs at 35 mph instead of 45 mph.

Trailer brakes, cooler and a tranny temp gauge are recommended.

A XJ was not intended to be a tow vehicle and it is what it is, but if you are careful, have a secured load, plan ahead and are lucky you shouldn't have any issues.

I forgot to add both XJ's mentioned are auto's.

With that said I'm looking into buying a Expedition/Tahoe/Yukon for towing duties since the 96 is now a trail rig and I would like to tow it to the trails now.

I'm still running my 29s with the 4.56 gears--pulled our 2500lb popup quite nicely this summer. It tachs 2500 @ 60 in OD which is quite comfortable. Milage was around 14 mpg, with three adults, armor, camping gear, etc.

Trany cooler.
If you do hills a LOT the 4.10 is the way to go.
With the stock tires and easy going I would give the 3.55s a try before putting any time/money into it.
Brakes The XJ will stop it self the trailer will stop it self. No need for oversized brakes.
I pulled 4280 LB for 6K miles two years ago and many more miles after . With stock brakes no problem.

just put in your data and find out what speed at what RPM

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

Ray H said:

I just ran it through a chart. I was off a little, At 60MPH you would be turning right at 3000 RPMs. Still seems a little high but your power would be good.

Click to expand...

I think that's just about perfect.

@ 50 mph (speed limit), you'd be sitting in the powerband, which would help for getting up the hills, but you wouldn't be winding the motor out too much... ~2500 rpm would be about right.