Torque Converter Tech...

I'm pretty sure my Torque converter is not locking up. I think that is leading to my over heating problem. My 87 overheates on the highway when it is hot outside on a grade (210-230). Electric fan is new on a manual switch. New 3 row radiator, clutch fan, water pump, thermostat, Cat & muffler. The problem has persisted through an engine change.
I never saw or felt a change in the tach when on the freeway when the TC is supposed to lock-up. I purchased Brets shifter that has a manual switch to lock up the TC, and it does nothing (the gear shifter portion works perfectly). No Lock-up. I have talked with him a couple times at I pretty sure it is hooked up right.
What could be keeping the TC from locking up? What can I look for? Thanks for any help.

Jeremy

Have you back flushed the entire system and got all the air out. For mine I take the top hose off and hook the hose up to it and let it run for a while. Last time I did it I flushed and added antifreeze. Never a problem since.

family TJ said:

Have you back flushed the entire system and got all the air out. For mine I take the top hose off and hook the hose up to it and let it run for a while. Last time I did it I flushed and added antifreeze. Never a problem since.

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Ya, flushed the system when I put the New Rad in. Then changed to an open System and put another new rad in and flushed it again. No change.

I'm pretty sure my cooling system is up to par...

Silly thought....does your brake switch work properly? On my 1992 this caused the TC not to lock up and of course also the cruise didn't work. Replacing the switch did it for me. This could all be very different on your 87, I don't know, but maybe something to check.

dutchjeep said:

Silly thought....does your brake switch work properly? On my 1992 this caused the TC not to lock up and of course also the cruise didn't work. Replacing the switch did it for me. This could all be very different on your 87, I don't know, but maybe something to check.

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Hmm... My Cruise control does not work either. I don't know if it is related to the cause of my TC not working or not. As for the switch, my brake lights work. Could it be faulty, but still let my brake lights work?

the brake switch thingy aspect is interesting. It must be deeper than just reading the application of the brakes to disengage either system. They must have adopted some enabling element to the system. That is, to assure that the brake interface was in some READY state.


..but ..I REALLY have a hard time with you not keeping coolant in control JUST due to the torque converter. Especially with all the goodies that you've got there for cooling. This has to be a shroud thing or an air flow thing.

100% assured way to prove it one way or the other. Ditch the rad tank cooler for an auxiliary and then it can have NO IMPACT on coolant temp.

It would be nice to get it fixed though.

on my '89 the cruise was not working and the problem was brake switch but the TC lookup was working also under this condition.
note: on '89 the brake switch has two output, one for the light and one for the cruise, if the cruise control not receive the signal @ power on disable the cruise.

geeaea said:

..but ..I REALLY have a hard time with you not keeping coolant in control JUST due to the torque converter. Especially with all the goodies that you've got there for cooling. This has to be a shroud thing or an air flow thing.

100% assured way to prove it one way or the other. Ditch the rad tank cooler for an auxiliary and then it can have NO IMPACT on coolant temp.

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I don't let it get hot enough to lose coolant. when it gets to 230 I back out of it, bring my speed down to 45-50 or so and let it get back to around 200-210 and hope like hell there are no grades or anything..

I have a new Fan shroud and Hood louvers. I don't think it's an air thing. My next step is a tranny cooler, but I think that WILL DUMP HEAT straight back into my Radiator.

One of the reasons I got an XJ to wheel, was the AC (for the wife and two daughters), and now I can't use it when it gets over 95!

marcoleo said:

on my '89 the cruise was not working and the problem was brake switch but the TC lookup was working also under this condition.
note: on '89 the brake switch has two output, one for the light and one for the cruise, if the cruise control not receive the signal @ power on disable the cruise.

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thanks, I'll look in to that... maybe at the very least I can get my cruise control fixed!

jrowell said:

Hmm... My Cruise control does not work either. I don't know if it is related to the cause of my TC not working or not. As for the switch, my brake lights work. Could it be faulty, but still let my brake lights work?

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Yep, brake lights worked fine on mine as well, but the switch was internally worn so that cruise and TC no longer were switched on. In other words, the switch gives the message that you're pressing the brakes so that TC and cruise are disengaged. It's really easy to check resistances over the switch to see if it works. If both TC and cruise don't work, it's a good change this may be the culprit! (Assuming it to be similar to my 1992.)

dutchjeep said:

Yep, brake lights worked fine on mine as well, but the switch was internally worn so that cruise and TC no longer were switched on. In other words, the switch gives the message that you're pressing the brakes so that TC and cruise are disengaged. It's really easy to check resistances over the switch to see if it works. If both TC and cruise don't work, it's a good change this may be the culprit! (Assuming it to be similar to my 1992.)

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I'll check that out tonight, thanks!

jrowell said:

I don't let it get hot enough to lose coolant. when it gets to 230 I back out of it, bring my speed down to 45-50 or so and let it get back to around 200-210 and hope like hell there are no grades or anything..

I have a new Fan shroud and Hood louvers. I don't think it's an air thing. My next step is a tranny cooler, but I think that WILL DUMP HEAT straight back into my Radiator.

One of the reasons I got an XJ to wheel, was the AC (for the wife and two daughters), and now I can't use it when it gets over 95!

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I keep forgetting this is a XJ <smacks head with realization>. That doesn't seem so out of whack then. I'd get the auxiliary cooler to buffer the trans. I wouldn't worry about the engine. If you want to increase your coolant buffering, pick up a laminar sandwich heat exchanger from any MOPAR counter. Just ask for the oil cooler for a 2005 Grand Caravan with HD towing package. It's the same one that I bought for my SE from the old MOPAR catalog ..but the nipples are angled a bit differently. You can also get one from ebay from the 80's Ford products ..but they're getting rare. If the parts guy is nice to you (shop around), you may be able to get it for about $100 ..but I think $135 is not too bad either. Ford typically got over $400 for them in the various configurations that they sold the Modine or Long units.

The lower one is an experimental MOPAR unit that never made it to production. The upper one is allegedly for an F150 ..they'll both fit your XJ without issues. The OEM unit has the nipples @ 90�° of the filter stud on the flat end (like the Ford unit, but stubbies).



It should give you a bit more capacity and delay your transitions a bit. Your oil will be at or near coolant temp ..so any moisture or volatiles will get flashed off in a timely manner ..even with relatively short trip usage. It locks my SE auto at the 205F point whether it's 95 out with the air on or worse as long as I'm moving. It used to sit at just above the 210F mark otherwise.

Good luck!

The easiest way to tell if it is locking or not is to shift from 3 to OD. if the rpm's jump about 300 then it settles back down then you know that it is locking.

geeaea said:

I keep forgetting this is a XJ <smacks head with realization>. That doesn't seem so out of whack then. I'd get the auxiliary cooler to buffer the trans.

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Well, that "seems out of whack" to me! Are you telling me it is normal that I can't use my AC when it gets hot outside, and I have to baby it to keep it in the 210 to 220 range! I don't think so. I will probably go with a trans cooler, but I don't think that willl help my motor cooling one bit, as heat will just be dumped straight to the radiator.

1985xjlaredo said:

The easiest way to tell if it is locking or not is to shift from 3 to OD. if the rpm's jump about 300 then it settles back down then you know that it is locking.

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I'm sure it is not locking. There is no change in RPM's.

GO CHIEFS!

Stupid question....but have you checked your fuses?? There is a fuse for the TC, as well as the CC....they may run together

*voice of experience*

jrowell said:

Hmm... My Cruise control does not work either. I don't know if it is related to the cause of my TC not working or not. As for the switch, my brake lights work. Could it be faulty, but still let my brake lights work?

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yup, there is two switches, one on the backside of the pedal that controls the brake lights and one on the front side that controls the torque converter lockup and cruise. Mine went out of adjustment and I was having the same problem as you.

RaccoonJoe said:

Stupid question....but have you checked your fuses?? There is a fuse for the TC, as well as the CC....they may run together

*voice of experience*

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Ya, I've been through the Fusebox a couple of times. Everything seems to be inplace.

Blue XJ said:

yup, there is two switches, one on the backside of the pedal that controls the brake lights and one on the front side that controls the torque converter lockup and cruise. Mine went out of adjustment and I was having the same problem as you.

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Interesting... did you just re-adjust it or completely replace it?

in my '89 there is just one switch with double terminal in parallel