Please help...Wanting 35s but i tow my boat lot. Stock 4:10s Rubi.
01-04-2012, 03:58 PM
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Please help...Wanting 35s but i tow my boat lot. Stock 4:10s Rubi.
Any suggestions or advise? I tow my boat a lot (2700 lbs) and just installed 2.5 TF lift. I don't have enough $ to do re-gearing. Should i just go with 33s? are 35s to big to affect my driving? I live in CA and there are some steep hills and i don't want to burn my trans. Anyone has the same setup? Thank you.
01-04-2012, 04:05 PM
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Good question. I would like to know to, as I have 3.73 going up to a 4" lift on 35"s, I never thought it might affect the towing. Somebody has to have the same setup as me or the OP?
01-04-2012, 04:43 PM
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Just turn OD Off, and take the advice on the trans cooler.
Check the charts in the drivetrain faq's and put some numbers to it. To get your OD Off, divide the OD On rpm by .69. You'll find that 35's with your stock gears and Od off isn't all that far from 5.13's with 35's and OD on. Where you will notice the big loss the most is low speeds off-road.
Check the charts in the drivetrain faq's and put some numbers to it. To get your OD Off, divide the OD On rpm by .69. You'll find that 35's with your stock gears and Od off isn't all that far from 5.13's with 35's and OD on. Where you will notice the big loss the most is low speeds off-road.
01-04-2012, 05:59 PM
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How big is your boat?
First you need 5.13 to put you back to stock performance on 35s.
Secondly, if you are using an automatic, prepare to burn up trannys. The 42RLE is not and I repeat NOT a transmission suitable for towing anything large. Its rated as a passenger car transmission. Its internals are weak sauce and they run hot due to the way they are programmed. The best thing you can do to prolong the life of it is do not tow anything and get the biggest cooler you can get your hands on. If you have to tow something, take it out of over drive. Allowing it to run in overdrive unlocks the torque converter too frequently generating lots of heat. Also keep in mind that the torque converter on this unit is tiny. It uses a very small clutch for lockup that is easily damaged by heavy loads on it.
I might also add that running incorrect gearing will keep the torque converter unlocked a lot of the time and it will generate heat in a hurry. It wont take much of that before every seal in the tranny is cooked and you lose pressure causing it to slip.
First you need 5.13 to put you back to stock performance on 35s.
Secondly, if you are using an automatic, prepare to burn up trannys. The 42RLE is not and I repeat NOT a transmission suitable for towing anything large. Its rated as a passenger car transmission. Its internals are weak sauce and they run hot due to the way they are programmed. The best thing you can do to prolong the life of it is do not tow anything and get the biggest cooler you can get your hands on. If you have to tow something, take it out of over drive. Allowing it to run in overdrive unlocks the torque converter too frequently generating lots of heat. Also keep in mind that the torque converter on this unit is tiny. It uses a very small clutch for lockup that is easily damaged by heavy loads on it.
I might also add that running incorrect gearing will keep the torque converter unlocked a lot of the time and it will generate heat in a hurry. It wont take much of that before every seal in the tranny is cooked and you lose pressure causing it to slip.
I got a 17' boat and trailer weighted at 2700 lbs. Even now on my stock Rubi 4:10 gears, i take it out of OD when towing the boat and i wont go over 65mph. I got a Flashpag tuned for towing. With what you said, Do i need the Trans cooler now even with my stock set up?
I might just stick with 33s for now. I know i will want 35s but with towing the boat almost every weekend, i think that will not be a very good idea.
Thanks ya'll.
Oh forgot to mention i got an Auto JKU Rubicon.
Last edited by OOC-07Rubi; 01-04-2012 at 06:02 PM.
01-04-2012, 06:08 PM
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Originally Posted by Wallsofcrete
6 speed Rubi here and towed a 19 foot camper (3200lbs) with no problem
01-04-2012, 06:23 PM
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I'm running stock tires now but buying 33s tomorrow (after i got the advice about transcooler) and the only performance stuff i got is a drop in high flow air filter and a superchips flashpag tuned for towing.
I dont have enough cash saved for re-gearing and new trans so decided to go with 33s.
I dont have enough cash saved for re-gearing and new trans so decided to go with 33s.
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01-04-2012, 07:14 PM
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Gears are 1-2 grand, a trans cooler is $60-$80 and an hour or two of your time to install it. Think of the cooler as a no-brainer for pre-2012 auto's, regardless of tire size. (I have read that they are factory equipped on the '12's?)
01-04-2012, 07:48 PM
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If my tranny burns up, Chrysler can replace it. They rate the JKU to tow 3500 lbs, so as long as I'm under that, I don't see why Chrysler should have a problem footing the bill.
01-06-2012, 02:08 PM
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I'm definitely getting a trans cooler. rather be safe than sorry. Thanks all for great advice.