[bennyoz]

I have a 73 HQ Holden sedan with a 350 sbc and turbo 400 transmission. I'm now looking at fitting the 3rd trans in it now as I have blown 2 of these now through abuse. I was wondering if there is anywhere I can get info online about rebuilds and what performance mods would be of benefit? I use the car on the street on weekends but would also like to be able to get optimun performance in case i finally get it to the strip. Any help would be greatly appreciated. Hopefully I will work out how to send photos so you guys can see what a HQ looks like.

 

[redsdad]

I'm kinda curious as to how your are blowing up TH400's with a 350. What is breaking?

I used quality rebuild parts, a Vega torque converter, and a home made shift kit. That tranny is probably still pulling that 2 ton drag car around somewhere.

Post some photos of your HQ. What year is it?

 

[Crosley]

I'd suggest buying a book & a video if you can find them .

Folks seem to like the Ron Session's book

 

[bennyoz]

Thanks guys

Thanks guys , I live in Australia and wondered what titles of Books or Manuals,websites or stores would have this kind of information. :thumbup:

 

[coupe66]

I bought the book - "How to Work with And Modify the Turbo Hydra-matic 400 Transmission".
Its by Ron Sessions, and have ISBN 0-87938-267-8 (ordered by any big bookstore)

The best book i ever bought... and if you fail to repair the trans with this book... :mwink:

And, if you manage to blow up an Th400 with an 350sbc, something is very wrong... like, no oil in the transmission! or something like that. Or are you driving them very hard without an external oilcooler, in an very warm climate ?

http://4x4trailhunters.com/pictures/article_21_8._Trans_Life_Chart_from_HECAT_Inc..jpg

If you tell us your config, and if something is changed, or maybe not TH400 parts installed ? (deep pan, stock pan) we are just guessing here...

/Pete

 

[bennyoz]

Thanks mate!

Thank you for passing on that information to me. Thats exactly what i'm after . :thumbup: In answer to your questions Yeah it gets pretty warm down here 40 degrees celsius. don't know what that is in fahrenheit sorry. The first trans blew hoses and chucked a front main seal, resulting in a cooked trans , it also had a cracked bellhousing. Don't know how that happened. Second one fitted with a large trans oil intercooler.This one was fine but suddenly sprouted leaks everywhere and has started slipping big time between 1st and 2nd. Don't know if it is an adjustment problem there I need to learn how to identify problems for myself and how to change seals and gaskets properly. I have found if I talk to a trans reconditioner guy that he either doesnt want know about it or gets that dollar signs look in his eye. Over here chev engines aren't cheap nor anything that bolts onto them .May as well be a ferrari . I have called a few speed shops but found most of them want megabucks for a hotted up trans. Besides, all the work on the car has been performed by myself and I want to keep it that way. I'm pretty lucky that my boss lets me fix my own stuff at work, so tools aren't a problem.
Thanks heaps again hope to talk again soon!
Yeah yeah!
Ben.

 

[400fbird]

i've found that turbo400's are VERY particular on fluid levels. If you have too much or too little they will slip.

 

[coupe66]

Symptoms for 1-2 slipping:

- Low oil pressure
- Valve body malfunktion
- Faulty rear accumulator
- Front pump malfunktion
- Leaks in case assembly

What kind of oil do you use?

My 400 trans had the wrong oil filler tube, and the wrong stick... think it came from an 350 trans.
The stick was too short, so some one had welded on an extesion... to get the" right" check level... :nono:

/Pete

 

[jakeshoe]

Ben,
The Th400 is one of the easiest trans to rebuild. Little tip for you, they also came in Rolls Royces, Jaguars, Ferraris, AMC's, and other non GM vehicles.

 

[dgcantrellsr]

Thank you for passing on that information to me. Thats exactly what i'm after . :thumbup: In answer to your questions Yeah it gets pretty warm down here 40 degrees celsius. don't know what that is in fahrenheit sorry. The first trans blew hoses and chucked a front main seal, resulting in a cooked trans , it also had a cracked bellhousing. Don't know how that happened. Second one fitted with a large trans oil intercooler.This one was fine but suddenly sprouted leaks everywhere and has started slipping big time between 1st and 2nd. Don't know if it is an adjustment problem there I need to learn how to identify problems for myself and how to change seals and gaskets properly. I have found if I talk to a trans reconditioner guy that he either doesnt want know about it or gets that dollar signs look in his eye. Over here chev engines aren't cheap nor anything that bolts onto them .May as well be a ferrari . I have called a few speed shops but found most of them want megabucks for a hotted up trans. Besides, all the work on the car has been performed by myself and I want to keep it that way. I'm pretty lucky that my boss lets me fix my own stuff at work, so tools aren't a problem.
Thanks heaps again hope to talk again soon!
Yeah yeah!
Ben.

Sometimes a busted case can be caused by a driveline that is too long, yoke needs about 1 1/2 inches slack so it doesn't slam into output shaft on hard acceleration, IE drag racing.