TH350 5,800 Rpm trans brake smoked trans

[johnmc]

well the 3 year old Monster transmission didn't like the new 598 BBC. it made some awesome passes and smoked up first gear bad on the last round of racing It still has second and 3rd. puked fluid out the dipstick. I need to pull it apart and see what let go. I hope i can rebuild it my self. it will be my first 350. What ever let go I need it 2 x stronger. It was a full race model reverse shift manuel. its been a good trans and has taken a lot of nitrous. I think I might go to a glide and chain drive over the winter.
any recommendations on first gear parts?

 

[johnmc]

well I pulled it apart. I have a rear planet is broken the 700R4 center support is marked up the wide roller clutch is black and rollers are 1/2 missing. the rear sprag is junk the snap rings on the sun shell are popped off and the bushing is melted Right out of the output shaft. I am thinking the cheep plastic bushing might be the cause of all this. don't know why someone would use a plastic bushing with a full race trans brake tranny.

 

[morrow07]

Because Monster cuts corners unfortunately. Sucks man.

Sent from my C771 using Tapatalk 2

 

[foamypirate]

Yep, heard nothing good about Monster transmissions, really. A friend's son had a "500HP rated" 700R4 from them that grenaded behind a stock TBI 350. Not exactly impressed.

 

[quaddriver]

plus, not to be a negative nelly, but the 350 tranny, even built, is torque challenged...hp ratings dont come into play until its moving and shifting, its that first stab where the torque of your motor (prolly a lot) broke things. Your teardown shows that it came apart rather efficiently. If the parts inside were of the proper quality, did the method of rebuilding really make THAT much of a difference? Would it have still failed in some way if done by the best guy?

You have a motor that wants to turn things, you have a heavy vehicle that does not want to be turned, the weak link is the tranny. GM used the 400 when 350 and 700's would bolt up, because they have to warrant them with some acceptable level of MTBF (mean time between failure) and they voted down the idea...you have what doubled? tripled? the stock hp of the MkIV?

 

[johnmc]

I want bashing monster. I have 4 of there transmissions in different trucks. I do have to say all of them have had problems. but its not worth sending them back because I have been there too.
But I think if that plastic output bushing was the better bronze one I don't thing i would have had all that side load on the shaft and broke everything. my truck is 2,900 lbs.4x4 with 1,000 hp it doesn't take much to get it moving . It has done a 200 ft track in 2.91 sec.
that tranny doesn't owe me anything .

 

[johnmc]

is there any reason this o ring is missing on the rear piston? is that a duel feed?

 

[Driver4r]

is there any reason this o ring is missing on the rear piston? is that a duel feed?

They do that so in theory theres more piston surface= holding force on the low clutch pack.

 

[Irishman999]

Plastic bushings can be put in place of brass ones, if the shaft is a little scuffed up you can just install a poly bushing instead. You can still get a good long service life out of a transmission with poly bushings installed.

Sounds to me like you need a TH-400, To make a 350 hold up to the power you have will cost a shitload.