TEXASS Posted July 6, 2007 Report Share Posted July 6, 2007 i couple days ago i ask for some tranny help. i have a TH400 with a B&M stall,4 months ago i put a 468 BBC in my everyday driver, 2 months after i put ithe motor in, the tranny broke in half on the bell houseing right in front of the pan,so 2 months later (today) this afternoon going to whitecastle i felt a vibration, looked under the truck the tranny was broke in the same damn spot as the old one. lucky jegs gave me a new one. heres a pic of the old 1st tranny i dont have a pic of the 2nd one but its looks the same. but i dont understand why it keeps on breaking any one have any clues? http://i95.photobucket.com/albums/l143/LOUD85GMC/Picture108.jpg http://i95.photobucket.com/albums/l143/LOUD85GMC/Picture107.jpg http://i95.photobucket.com/albums/l143/LOUD85GMC/Picture.jpg Quote Link to comment Share on other sites More sharing options...
KillJoy Posted July 6, 2007 Report Share Posted July 6, 2007 Too much Power, or poor construction??? KillJoy Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 6, 2007 Author Report Share Posted July 6, 2007 it made 503HP at the crank and 300 at the wheels, so i dont know Quote Link to comment Share on other sites More sharing options...
KillJoy Posted July 6, 2007 Report Share Posted July 6, 2007 it made 503HP at the crank and 300 at the wheels, so i dont know That would be a 40% loss due to the driveline. That seems HIGH to me. Are these stock replacements? Or built for power? It should be built....IMO. KillJoy Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 6, 2007 Author Report Share Posted July 6, 2007 That would be a 40% loss due to the driveline. That seems HIGH to me. Are these stock replacements? Or built for power? It should be built....IMO. KillJoy well its a 2 peace driveshaft with a carrier bearing turning 14inch drums,the only problems i had since the motors has been the the truck is the broken trannys and getting enough fuel to the motor Quote Link to comment Share on other sites More sharing options...
KillJoy Posted July 6, 2007 Report Share Posted July 6, 2007 well its a 2 peace driveshaft with a carrier bearing turning 14inch drums,the only problems i had since the motors has been the the truck is the broken trannys and getting enough fuel to the motor But....are these built Trans' or stockers??? KillJoy Quote Link to comment Share on other sites More sharing options...
Guest No-cones Posted July 6, 2007 Report Share Posted July 6, 2007 it made 503HP at the crank and 300 at the wheels, so i dont know Thats alot of loss, I think 15% is the normal for loss Quote Link to comment Share on other sites More sharing options...
V8 Beast Posted July 6, 2007 Report Share Posted July 6, 2007 503 to the crank should be 400 to the wheels. That looks like poor manufacturing. The core has weak points and is cracking until you get the end results in the pic. Quote Link to comment Share on other sites More sharing options...
MaverickGrabber1972 Posted July 6, 2007 Report Share Posted July 6, 2007 Looks to me like the trans is binding ..the motor is twisting and flexing pushing the bell against the body and snap …seen this with solid trans mount on the trans and reg old rubber motor mounts. look around the trans tunnel see if you can see where it may be hitting .............something is binding ..its not the case…..TH400 are tuff …now if it was a TH350,,,,,,,,,,, That or the engine mounts are weak and there is to much weight one the trans Quote Link to comment Share on other sites More sharing options...
Tinman Posted July 6, 2007 Report Share Posted July 6, 2007 Did you by any chance forget the transmission dowel pins on the new block? Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 6, 2007 Author Report Share Posted July 6, 2007 Did you by any chance forget the transmission dowel pins on the new block?no they are there Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 6, 2007 Author Report Share Posted July 6, 2007 But....are these built Trans' or stockers??? KillJoy its a super street fighter TCI TH400 Quote Link to comment Share on other sites More sharing options...
AJ Posted July 6, 2007 Report Share Posted July 6, 2007 what engine mounts do you have? what transmission mount do you have? Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted July 6, 2007 Report Share Posted July 6, 2007 you need to check and see if the bbc setup for your truck uses a different driveshaft than the stock sbc one your using now check the carrier bearing and make sure its not broken or chnage to one piece drive shaft if thats all kosher your tranny mount needs to be softer than your engine mount the picture looks like the engine is moving but the trans isn't so check for broken or loose motor mounts also worst case run a block plate and rubber trans mount hope this helps Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 6, 2007 Author Report Share Posted July 6, 2007 the motor and tranny mount are rubber and were replaced after the 1st one was broken. i went to jegs and bought motor plates for it today. i hope the fixes it Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted July 6, 2007 Report Share Posted July 6, 2007 how far does the slip yoke go into the trans whewn you install the front driveshaft? if it bottoms out or is close have it shortened a little bit Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 12, 2007 Author Report Share Posted July 12, 2007 if the motor is not inline will that break it? Quote Link to comment Share on other sites More sharing options...
Buckeye1647545503 Posted July 12, 2007 Report Share Posted July 12, 2007 When you put the trans in is it laying flat againest the block with out the bolts? You should NEVER use the bolts to "pull it together" Quote Link to comment Share on other sites More sharing options...
TEXASS Posted July 12, 2007 Author Report Share Posted July 12, 2007 no not like that, idont kow how i missed this, i put new motor mounts in the truck about 2 months before i put the BB in. but i did'nt think is there a differnce between sb and bb motor mounts. so my only guess is i have has the sb motor mounts in there the whole time and its not inline. Quote Link to comment Share on other sites More sharing options...
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