Parleys Canyon/Torque Converter

[troutlips]

https://www.turbodieselregister.com/ubb/icons/icon5.gif My son has a 98, 12 valve that has been turned up. New plate, mystery switch and aneroid adjustment, with 4" exhaust from the turbo back. He is running #30 pressure and 1200 degrees mounted aft of the turbo. Question is should he run with the converter on when pulling hills (6% grade) with trailer (~6000 #).

Given that he should be out of overdrive he is overheating the old Cummins to just below red line. I have had a standard transmission for the last 10 years and have not paid attention to the auto transmission problems. Your thoughts... ...

 

[Joe G.]

If you tow heavy with the TCC manually locked you will eventually thrash it. In fact, if you don't have a way to force it to be unlocked in this situation you may thrash it anyway.



1000 degrees EGT post turbo is supposed to be maximum to avoid piston melt down.

 

[Fistfull]

Parleys Canyon will definately generate a huge amount of heat in an auto, been there done that, the pan was FULL of clutch lining when it was all said and done.

If you do this often, add some additioinal fluid cooling capabilites ifn you want it to live for very long, maybe back off the power and the engine will live longer too man that's toasty

 

[chuck3]

How fast is he going to get that temp. ? I have been up parleys several times with my Trailer at about 6 to 7k and I pull it at 65 in 3rd lockup and only see about 900 to 1000 deg. on my gauge.

 

[Cooker]

I think everyone has you covered here.



I agree keep the EGT's down. 900 post turbo is what I've read plenty of times about being the max temp. I would venture a guess that 1000 in short burst is ok.



If the TC stays locked up this grade with 30psi of boost towing anything, it will have a very short life.



Ryan

 

[amsoilman]

troutlips,

I just pulled "Parley's" this past week-end. The temp your son is running is too hot! Tell him to back out of it if it reaches 1000 degrees! TCC on my own truck is locked going up parley's, but I do have a modified VB and an aftermarket TC, and run the Amsoil synthetic ATF in it as well. Trans temp over parley's stays around 150 degrees when TCC is locked going up that canyon.



Wayne

 

[BushWakr - RIP]

If your pyro is mounted post-turbo you should factor in the following rough formula to your total temp...

add 10*F for every 1 lb. of boost. So...

30psi boost is about another 300*F. pre-turbo.

If your running 1200*F 'after', then you are darn sure up to 1500* F. in real time. That is WILD!

ps: I'd stand back a ways and grab an extinguisher... . but thats just me.

 

[HoleshotHolset]

To recycle all those pesky pieces that came out of your engine when you exceeded the maximum safe EGT... install a set of skid-plates, or as I like to call 'em..... "failed parts collection coordinators"



Matt

 

[troutlips]

Parleys Torque question

He has a torque converter switch and leaves it off all the time. When should he use it? Only on the flats?

 

[HoleshotHolset]

When the torque converter clutch (hereinafter referred to as: TCC) itself engages it makes a tremendous amount of heat... . this heat is very quickly dissapated into the fluid and everything is usually kosher. However, if you go running around for extended periods of time with the TCC disengaged manually... transmission temps will rise due to the non-mechanical (fluid) coupling between the engine's flexplate and the input shaft of the transmission via the torque converter/TCC.

My truck has 4. 10:1 gears... and it would be nifty if the TCC wouldn't engage at 40mph all the time... it likes to shudder at that rpm/mph. It also engages at 35mph with OD locked out... grrr!

DTT valve body and TC upgrades are the key to eliminating this severe annoyance.

Hope this helps a bit.



Matt

 

[Joe G.]

I'm not so sure I agree with heat build up because of running around for an extended amount of time with the TCC manually disengaged. That's exactly the situation with the 37RH transmission used in the '93 trucks. It's almost exactly the same as a 47RH except that it has no TCC. A close friend has one of these and tows a big fiver a lot. No sign of excessive temps with his rig. Even on SR58 from Bakersfield to Mojave. It gets warm on these kinds of grades but not excessive. Of course, he has only turned up the pump a little. Nothing heavy in the BOMB department. You can get excessive temps if you use an exhaust brake in 2nd without the TCC being locked for a long steep grade. If you have a DTT VB and TC it does provide lockup in 2nd to avoid the temps. Love mine!!!!

 

[HoleshotHolset]

Hrmmmm... .

An auto transmission with a torque converter that has a TCC reacts very differently to running with the TCC disengaged than an auto transmission with no TCC.

If you run without your TCC engaged on a transmission that has it... you get higher temps..... a transmission without a TCC is a different beast and may run with cooler temps because it is designed that way - to be run 100% of the time with no mechanical coupling.

This has been my experience... ...



Matt

 

[Joe G.]

I haven't seen that with the 47RH in my '95 so far. I've made a couple of trips to and from Sacramento (about 300 miles) with several pretty good grades with the TCC disengaged since I got my DTT stuff. So far, so good. The sloppy stocker might heat up. I don't know about that from direct experience. I think my friend's 37RH has a more efficient TC than the stock 47RH because his PakBrake works pretty good and mine didn't work at all until I installed a manual lockup switch for the TCC. His brake will maintain 55MPH going down the Donner grade going east pulling his fiver. Not as well as a locked TCC, but it does work. No sign of excess heat when he does that.

 

[danandamy]

"Sloppy stocker" LOL, I like that. I think you hit the nail on the head. With my DTT stuff, heat is really pretty much a non issue. Oh, don't get me wrong, I watch the temp gauge but I haven't seen anything excessive. In fact, when pulling, I'm seeing very little difference in temps between lock-up and fluid coupling. I hit a big hill and I reach up and flip the "unlock" switch and pour the coals to it and never have to worry about smoking the converter clutch.

 

[HoleshotHolset]

Yeah, seems as though we have answered our own questions now. I had always wondered if the 1st Gen trucks had TCCs in 'em or not.....

The stock 47RH converter isn't worth it's weight in manure.

The DTT unit won't generate as much heat because it is more efficient... ... when a fluid coupling device is generating excess heat... . that's a sure sign of a transfer of power that needs improvement.

If your friend's 37RH without a TCC is working better with his exhaust brake than a 47RH with a TCC then that is a dead giveaway that it is operating more efficiently than it's counterpart that has a TCC.



Matt - I love my truck, but my transmission hates my engine (and my right foot!).

 

[Joe G.]

Matt,



I just got an e-mail from my friend with his '93 "Old Iron Wheels" and thought I would share a couple of quotes:



"There was some pretty good grades after Arcata and before Klamath. The Ex. brake did hold the Truck going down the 6% grades BUT when going down the 7% I had to use the service brakes as well. "



I tried that with mine before I installed a manual lockup switch for my TCC and I scairt my widdle self.



"I saw a lot of first Gen. Trucks on this trip, most of them pulling 5th wheels. We came down the coast and went 299 to Redding on the way back. Holy Moses is that a pull from the west side and those curves were terrible. never again with a Trailer. I had to use 2nd gear up the west side for a spell. The truck did not get hot and the Trans. did not go over 200,but the Horton fan

sure got a good work-out. "



No TCC in his rig so the TC must be better than the sloppy stocker in a '95.

 

[BushWakr - RIP]

FWIW, my 93 does not have a 37RH. I believe they came with (as mine did) the A518 w/od.

Maybe they are the same transmission, i don't know. There is NO lock-up, just OD.

If you hammer it when it first slips into OD, say aroung 35-40MPH then hang on to your temp gauge!!! Since Bill K did a service/adjust its a bit better but you can still hit some scary temps.

I have bailed out (of the power pedal) when its hit 235*F. Bill says they can go up to 250*F or more (1st Gens) frequently if pushed and powered. Its not good of course but the 1st Gens all ran hotter than the 2nd Gen trannys. Also apparently the VB's in the 1st Gen trucks push oil better'n the newer ones. By that i mean that theres less need to slip it into 'N' instead of 'P' when stopped to improve oil flow/cooling.

JMO

 

[HoleshotHolset]

Sounds like you have some pretty serious hills out that way that would make owning an E-Brake almost essential to survival. I have yet to tow anything with my truck so I guess I don't really need one yet... ...

It is unfortunate that the TC's in the '94 and up are really loose... . but I guess we gain a little by having lockup. Bill K's parts and mods are no longer considered a luxury, they are a necessity.

Thanks for the info!

Keep 'em in boost!



Matt

 

[Joe G.]

BushWakr,



There is a bit of confusion about which transmission is in my friend's truck. The truck is a late '93. He thinks it is a 37RH but it might be an A518. The tag inside the hood is too faded to read. It's probably like the old Imperial I have. That car came with either an A-727 or A-904. Not much difference between them, mostly in the low-reverse gear stuff. All of them are some sort of Torqueflite.