Juice79

I have a Trailblazer SS AWD with a few minor bolt-ons. Tranny mods are Sonnax Servos and a Vig single disc 3600 stall. Stall was installed about 2000 miles ago and the truck ran great. Yesterday I had the truck on the dyno doing some pulls for tuning purposes...we were NOT locking the TC at WOT since I do not lock it when running at the track. In between runs the front pump seal blew and the tranny fluid leaked out all over the place. My question is could the seal have blown because of the heat generated during the dyno sessions or is this a result of perhaps a faulty install? Would this have likely happened anyway regardless? I am just looking for info on what could cause this to happen as I obviously do not want this to happen again.

Once the tranny is out the shop is going to check the bushing and front pump to ensure there wasnt any other damage done. Now that the trans is coming out I figured I mind as well have it fully rebuilt for that added peace of mind.

And on the bright side it happened at the shop and not on the street so I wasnt stranded and didnt have to pay for a tow. Thanks for any input guys!!!

FLT

iTrader: (1)

To be honest with you I have not seen many front seals blow out. I would have to believe that the front seal was damaged by a bushing that either walked forward or had spun and damaged the seal. This does happen over time. However I have seen where when the converter was installed by a gorilla and the Teflon bushing was damaged. This could cause the problem at hand as well. Not to point fingers at the installer, but this is a sensitive area when installing the converter. It happens trust me! Vince

Juice79

A buddy of mine mentioned that perhaps because, within my tune, I changed the converter lock up pressures I may have caused this....Is this possbile if I commanded to much pressure?

FLT

iTrader: (1)

I do not believe that to be true. I would almost bet the bushing has spun. Let us know what you find when it comes apart. Vince

Gilbert@Ace Racing

Hey Juice... how many pulls had you guys made and in what timeframe prior to the failure?

I can say that I have seen countless trannies fail on chassis dynos personally. There are too many variables to try to determine what happened here without seeing it fisrt hand. Heat can do strange things in high rpm situations... but I would like to know what everything looks like prior to suggesting anything. Vince covered all the usual suspects and there is not much more that can cause the frt seal to fail. I would think that if it went 2k miles then it would not likely be related to the converter install.

g

performabuilt

iTrader: (25)

I do not think this is the issue, likley the seal blew as mentioned from a bad bushing and I have seen them blown due to temperature, But not generally with seal retainer. We mod our bushings to make it impossible for them to move or spin

Juice79

Total of 3 pulls...First 2 within 15 min of each other...last was about 1 hr later. Then about 15 min later when we started it up to do another pull we saw all the tranny fluid.

Juice79

Total of 3 pulls...First 2 within 15 min of each other...last was about 1 hr later. Then about 15 min later when we started it up to do another pull we saw all the tranny fluid. Once they get the tranny out and tell me what failed I will update you guys. Thanks

Greaseymec

iTrader: (9)

I,ve got one on the bench at the moment that the front seal went Customer wanted some upgrades while it was out. Bushing was still in place, retainer and seal was still there and in place. I took a good look at the seal and it was not split, torn, creased etc. Only thing I can think of is that the seal lip simply popped foward on the converter hub. What ever the situation he lost the full contents of the pan in a few blocks. No real damage otherwise.

Mec

performabuilt

iTrader: (25)

Like I said I have seen them do it from heat metal/aluminum expansions rates , We use super locktite along with the retainer with ours

Greaseymec

iTrader: (9)

Good idea.

Mec