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Did I overcool my tranny? Or is 100 to 120 normal?

99xjclassic

NAXJA Forum User
Location
Michigan
I just installed a B&M supercooler with a B&M trans temp guage on my 99 XJ. (Thanks to all the help on this forum) I put my cooler after the radiator in the trans return line. So I go trans->radiator->cooler->trans. I also installed my gauge on the return line 4 inches from where it goes in the trans. It seems like it takes alot of time for my temp to reach 100 degrees, the highest temp I have seen is about 150, but that was when I was making the trans work lol. It for the most part doesnt go higher than 100-120.. Am I overcooling my tranny? Could it be one of my connections and maybe a gauge malfunction. This is driving me insane,please help!
 
you are measuring how well your coolers are working. for an accurate reading of the trans temp the guage should be on the output line of the trans, not the return line.
 
Mine runs about the same. Without the cooler it took about a half hour to reach 150. Now with the cooler it takes quite a bit longer. It gets warmer on the trails, but not too much.
 
Good to hear guys! Yeah I know I installed it in the return, thats just what the directions stated, maybe I will have to install one on the feed line as well
 
Same here. Same set-up and all.
It doesn't even register while on the freeway. It'll get warmer while driving a carload of people at the beach in soft sand. I need to put in another temp sensor so I can have an in and out reading.
 
The in temp is all that matters. The out temp is only a concern if the in temp is too high.
 
About 180 or less. 200 or less if you are beating on it.
 
GrimmJeeper said:
you are measuring how well your coolers are working. for an accurate reading of the trans temp the guage should be on the output line of the trans, not the return line.

X2
 
You can try calling Summit or B&M and get a second T fitting and sender. The rig a double throw toggle between the two senders and you can monitor both temps (feed and return).

I'd go that route over pathing the current one to install another.
 
You're doing it the right way, don't worry about it. Yes, the trans should be able to warm up in cold weather, but if you're consistantly over 100 you're probably OK. If it doesn't get warmer than that during your commute in cold weather, you can install a cooler bypass valve that many trans cooler places sell.
 
Goatman said:
You're doing it the right way, don't worry about it. Yes, the trans should be able to warm up in cold weather, but if you're consistantly over 100 you're probably OK. If it doesn't get warmer than that during your commute in cold weather, you can install a cooler bypass valve that many trans cooler places sell.


Pretty sure the B&M super cooler has the built in bypass until the fluid hits a certain temp.
 
Yeah my B&M has a "low pressure drop" or something like that, that operates on the viscosity of the fluid. Driving on the freeway and short commutes in the city I rarely see 100..Maybe i will install a sending unit in the feed line as well.
 
99xjclassic said:
Does anybody know if I can just buy a unversial sending unit to run in conjunction with my B&M trans temp gauge?

Hey, if you're that into doing work on your rig that you don't have to do, you can come and help me work on mine. :D
 
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