Need Help with 400 tranny.. very frustrated

[Team Bocker]

Okay so we have been having issues with our 400 tranny in our mud truck for the last year.  They are constantly getting fried!!!  We replaced our fly wheel and make sure that the fluids are adequate and almost every time we run our truck the tranny goes and we arent sure if there is a way to beef it up if maybe we are using too much horse power for the tranny or WTF the problem is can some one send us some advice of any kind...   would sure be appreciated- we are heading back out to the shop to once again take the tranny out of the truck...

[OLD SCHOOL]

flush your tans lines,replacing your trans.cooler, new torque convertor.  A th400 is a very tough trans. something is going on ?

[MR NASTY]

yup once you fried the trans you also killed your converter  id get a different case maybe?  also a big cooler and a fan should help

[Team Bocker]

We dont run the truck for very long...  top five minutes at most.  Our case is a 205 gear driven.  And you kill your converter everytime you fry a tranny??

[betterbeaters]

after you fry a trans have the converter flushed and inspected! what motor tires and gears you got? stock trans rebuild or used ones?

[Team Bocker]

we have a chevy 454 bb about 600 horse 6.71 or 2 geared and 2.5 rockwell axles with super swamper bogger 44s  rebuilt 400 tranny with a transpak.  Besides turning the converter upside down and draining it how else do you flush it???  thanks so much for the help

[betterbeaters]

you have to send it out have it cut and cleaned last I knew. I would find a good trans guy and have him build it to your truck the more money you spend the stronger it will be lol

[MidMichiganMudRun]

Buy a new converter everytime you burn up a tranny

[RIP_K52007]

definatly dont reuse a converter off a burned up tranny, and with that much money invested id run new lines and a cooler as well. Dont want the burned up clutch particles and all that getting pumped threw your new trans.

[4x4xdodgeman]

its your coverter burning up the trans.  80% of the heat in trans comes from the converter.  step up to the plate and buy a good converter!!!!    look how much have you spent $$$ on trans rebuilds?   is it between $400.00-$1000.00?  spend $500.00 -$1200.00 on a converter. i have used the same trans and converter for 15 years with no problems. trans has $60.00 rebuild kit.

[OHEARN.2012]

yea always make sure you flush your coolant lines with a air hose and some brake clean. if you dont you just reuse all that old nasty fluid in your cooler back in trans

[KORNBREAD]

Wow with that set up id have the trans sent out and fully built and tuned to what your running.  And yes Alex (betterbeaters) is right you need to send the tourq converter out to have it flushed and redone properly. But if you do like everyone said and just spend the cash to have the trans and converter built up to handle what you run you will get alot more life out of that trans.

[J.C.]

if i ever had a problem, id call mudman. he rebuilds them right, and he does awesome work!

[old school truck dude]

we have a chevy 454 bb about 600 horse 6.71 or 2 geared and 2.5 rockwell axles with super swamper bogger 44s  rebuilt 400 tranny with a transpak.  Besides turning the converter upside down and draining it how else do you flush it???  thanks so much for the help

Turnin it upside down wont get it all out. When you fry a trans all the shavings travel through the entire trans and convertor. You should probably get a new convertor when the trans is fixed this time, or some trans shops cut the convertors open on a lathe to clean them out and make modifications such as removing vanes to increase the stall speed. You must clean it all out completely to be safe. Anytime there are shavings in there, you gotta take it completely apart and start all over to get them all out, or you're gonna be doin it over and over. Sounds like you might not be gettin all the shavings out. The shavings plug up the filter and starve it for fluid, which causes it to slip, once it slips, you're done. You should replace the lines and have the cooler flushed professionally so you can start off fresh. Best to start all over and let Mudman do it, he will do it right and he knows what it takes to make one hold up.

[Blazin40s]

Always change out converter!

[OHEARN.2012]

if i ever had a problem, id call mudman. he rebuilds them right, and he does awesome work!

we have a chevy 454 bb about 600 horse 6.71 or 2 geared and 2.5 rockwell axles with super swamper bogger 44s  rebuilt 400 tranny with a transpak.  Besides turning the converter upside down and draining it how else do you flush it???  thanks so much for the help

Turnin it upside down wont get it all out. When you fry a trans all the shavings travel through the entire trans and convertor. You should probably get a new convertor when the trans is fixed this time, or some trans shops cut the convertors open on a lathe to clean them out and make modifications such as removing vanes to increase the stall speed. You must clean it all out completely to be safe. Anytime there are shavings in there, you gotta take it completely apart and start all over to get them all out, or you're gonna be doin it over and over. Sounds like you might not be gettin all the shavings out. The shavings plug up the filter and starve it for fluid, which causes it to slip, once it slips, you're done. You should replace the lines and have the cooler flushed professionally so you can start off fresh. Best to start all over and let Mudman do it, he will do it right and he knows what it takes to make one hold up.

yea mud man is a great guy to get trans done thru he does good work at good prices

[Disturban]

When you get a new tranny in it I would also suggest using Dexron XI it is a far Superior fluid vs Dexron III, everything about it is almost twice as good, notice they didn't even bother with Dex 4 or 5?  I did a filter change and full flush using Valvoline Dexron VI on my wifes truck as well as a few family members vehicles, the difference in shift quality is night night day.

Here are the benefits of Dex VI http://www.sandyblogs.com/techlink/2009/05/dexron-vi.html

[old school truck dude]

Back "in the day" we used Ford type F fluid, it made the chevy trans shift much firmer

[Team Bocker]

okay what we are doing is going back to a stock torque converter 12 inch diameter...  if the cam is too big we will just use neutral more, to try and eliminate some heat and extend the life- a few people we play in the mud with has suggested this to us.  we will be taking our trannny back to our buddy joe up in boyne city.  gonna put a trans pak in the other tranny so we have two of them ready to go that WILL NOT shift on us we are gonna put in a new cooler and remove the lines and clean them- depending on how nasty everything is coming out of them will depend on if we replace them or not-  also make sure there is a new filter put on each of our trannys-  please let us know if any one has any more suggestions or input on our plan-  we sure do appreciate all the help Mike and Kristen

[old school truck dude]

Just be very thorough and dont leave anything to chance and you should be fine, sounds like youre on right path..