351 C4 guys...question on front main seal lifespan

Stang_ROTY · 06-26-2008, 11:15 PM

--------------------------------------------------------------------------------

THe other day I had the pleasure of losing a front main seal on my C4 MIghtMite tranny from Dynamic Racing while shifting hard from 2nd to 3rd. Big smoke show

I have about 2000 miles total on the combination over 3 years and about 35 passes at the strip. Been a VERY reliable setup. I'll be yanking the motor ASAP to replace seal. Cause for concern or typical wear?

goodyear1984 · 06-28-2008, 09:22 PM

make sure there is no play in the shafts..also make sure the pump is not whats leaking

Stang_ROTY · 06-30-2008, 06:34 AM

By that you mean the input shaft? Is there any way to tell if the pump is the cause without pulling everything? I put about 2 gallons into it and about 5 seconds after I started it up it came pouring out the bottom of the bellhousing

Quote:

Originally Posted by goodyear1984

make sure there is no play in the shafts..also make sure the pump is not whats leaking

goodyear1984 · 06-30-2008, 06:21 PM

u really have to pull it out and inspect it what ever it is should stick out.

goodyear1984 · 06-30-2008, 06:24 PM

you could do a pressure test but with it leaking like that it would be point less ,,,plus u dont want to run it low on fluid and have to replace the clutches and bands

Stang_ROTY · 07-01-2008, 09:34 AM

Yeah that's a good point about running low on fluid. I lost all 3 gears when trying to get her home during the massive leak. Ended up about a 1/4 mile away when I lost all my gears. Tranny was bone dry. I'm running a temp gauge and didn't notice any increase in temp so hopefully it's ok internally. I'm going to bring it back down to Harold at Dynamic Racing to have them look at it. I went with the automatic setup over a 6 speed b/c I figured it'd be more reliable. But maybe the 2500-3000 rpm traveling on the highway to the track hurt it? I can't imagine 30-40 12 second passes on a tranny that's made for 8 second Stangs did any abnormal wear.

This wasn't a cheap tranny at all...I'm a bit surprised (and disappointed) that seals are going this soon.

Quote:

Originally Posted by goodyear1984

you could do a pressure test but with it leaking like that it would be point less ,,,plus u dont want to run it low on fluid and have to replace the clutches and bands

06-26-2008, 11:15 PM	#1
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	351 C4 guys...question on front main seal lifespan -------------------------------------------------------------------------------- THe other day I had the pleasure of losing a front main seal on my C4 MIghtMite tranny from Dynamic Racing while shifting hard from 2nd to 3rd. Big smoke show I have about 2000 miles total on the combination over 3 years and about 35 passes at the strip. Been a VERY reliable setup. I'll be yanking the motor ASAP to replace seal. Cause for concern or typical wear? __________________ Red 1993 GT Street Machine Best E.T. - 12.41/Best MPH = 108 Engine is a 1969 351 block w/393 stroker kit. Dynamic Roller Myte C4, 8 pt cage. Edlebrock Performer heads and Victor Jr. EFI, FRPP 30lb injectors & Cartech fuel system. MSD ignition. Sothside Machine bars & Sub-frames, adj. upper's, 3.73's, Koni rear shocks, much more

06-28-2008, 09:22 PM	#2
goodyear1984 Registered Member Join Date: Dec 2006 Location: new york Posts: 482	Re: 351 C4 guys...question on front main seal lifespan make sure there is no play in the shafts..also make sure the pump is not whats leaking __________________ 347 stroker all forged,arp everything,stud mains w/girdle,7qt pan,full roller, custom cam, aluminum heads swirl valves 5 angle valve job.quick fuel 750,areomotive pump,cobras w/nitto drags,and m/t et drags for the track, ford racing 373 gears,centerforce clutch,tko500,underdrive pulleys,bassani x-pipe,flowmasters ^best et so far 11.6 1.61 60ft coming soon 9sec et's 1992 mustang gt 2001 gmc 1500 4x4 78 century boat 92 skidoo

06-30-2008, 06:21 PM	#4
goodyear1984 Registered Member Join Date: Dec 2006 Location: new york Posts: 482	Re: 351 C4 guys...question on front main seal lifespan u really have to pull it out and inspect it what ever it is should stick out. __________________ 347 stroker all forged,arp everything,stud mains w/girdle,7qt pan,full roller, custom cam, aluminum heads swirl valves 5 angle valve job.quick fuel 750,areomotive pump,cobras w/nitto drags,and m/t et drags for the track, ford racing 373 gears,centerforce clutch,tko500,underdrive pulleys,bassani x-pipe,flowmasters ^best et so far 11.6 1.61 60ft coming soon 9sec et's 1992 mustang gt 2001 gmc 1500 4x4 78 century boat 92 skidoo

06-30-2008, 06:24 PM	#5
goodyear1984 Registered Member Join Date: Dec 2006 Location: new york Posts: 482	Re: 351 C4 guys...question on front main seal lifespan you could do a pressure test but with it leaking like that it would be point less ,,,plus u dont want to run it low on fluid and have to replace the clutches and bands __________________ 347 stroker all forged,arp everything,stud mains w/girdle,7qt pan,full roller, custom cam, aluminum heads swirl valves 5 angle valve job.quick fuel 750,areomotive pump,cobras w/nitto drags,and m/t et drags for the track, ford racing 373 gears,centerforce clutch,tko500,underdrive pulleys,bassani x-pipe,flowmasters ^best et so far 11.6 1.61 60ft coming soon 9sec et's 1992 mustang gt 2001 gmc 1500 4x4 78 century boat 92 skidoo

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
main seal..	89GTimporteater	Windsor Power	5	11-26-2003 01:50 PM
rear main seal	racerx0071	Windsor Power	1	02-19-2003 02:18 AM
Rear Main Seal	1hot5.0	Windsor Power	9	09-10-2002 06:22 PM
Rear main seal	RPM427	Windsor Power	6	06-24-2002 11:42 AM
Rear main seal on 87 2.3L	Radon	Small Ponies	1	02-20-2001 03:08 PM