Freshly rebuilt 700R4- Leaking Input Shaft Seal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Dakota Kid · 01-09-2006, 05:55 PM

Just had my 700R4 rebuilt by a local shop. I pulled and installed the tranny, not fun at all in my book. I haven't driven it ten miles yet. Didn't have leak until today, I warmed it up and was going to take it to the trans shop to make sure my TV cable adjustments are OK. I noticed a small puddle, and after taking the flywheel cover off, it looks like the input seal is leaking. What could have happened?? I slid the convertor on, made sure it was seated. It rotated freely when not bolted to the flywheel. I wondering what I should do, a brand new seal shoulnd't be leaking, and I don't think I could have screwed anything up. Suggestions?? Thanks

DK

bglad420 · 01-09-2006, 05:57 PM

Did you put the tranny and coverter in as one unit???? cuz if you bolted the converter to the flexplate and then put the tranny up you might have blown the front pump.......Or it might just be the front seal the I put a new tranny in my car, and the seal just went out 2 days later...**** happens(I hope its your front seal)

You know what check your dipstick tube make shure the o ring is ok, my blazer liked to leak from their....It drove me CRAZY!!!!!!!

**Green Machine** · 01-09-2006, 08:25 PM

The convertor hub should be lightly greased or at least oiled before putting into the trans. If it was installed dry, it can wipe out the seal before it gets oil. Tranny can also leak between the front pump and the case, or around a front pump bolt. Sorry, but looks like R&R time.

Dakota Kid · 01-10-2006, 01:08 AM

Tranny and convertor were put in together, then bolted to the flexplate. Hub was lightly greased when put in. I thought it may have been a pump bolt, but it looks like the input seal. I have checked the dipstick, cooler lines etc. It really wasn't fun to take in/out, and I really don't have the time to do it. I was just getting ready to sell it when the tranny went south, now a grand plus later and here I am where I started. Thanks for the help.

**VetteVet** · 01-10-2006, 09:03 PM

Here's some good reading on the 700r4
http://www.transmissioncenter.net/700R4.htm

Dakota Kid · 01-14-2006, 06:19 PM

Any chance overfilling the tranny could spit some out the input shaft? I was overfull, now I am just a bit over. Fluid level shows just below the bottom of warm when cold. Started it up today, drove it a bit, and don't seem to have a leak?? WTF?? Just hoping it doesn't pop up again later.

3100 special · 01-15-2006, 07:06 PM

Quote:

Originally Posted by VetteVet

Here's some good reading on the 700r4
http://www.transmissioncenter.net/700R4.htm

Great information! Thanks for posting that link!

**VetteVet** · 01-15-2006, 08:35 PM

Quote:

Originally Posted by 3100 special

Great information! Thanks for posting that link!

You're very welcome, I must have 25 or thirty of them. This is one of my favorites also.

http://images.google.com/imgres?imgu...l%3Den%26lr%3D

Dakota Kid · 01-15-2006, 09:33 PM

Thanks for the input. Sad story, but it is leaking again. Going to have to yank it out again

Not real happy, but what can one do?? Should go a bit easier now that I've had it out once.

**VetteVet** · 01-15-2006, 03:05 PM

It might cause fluid to leak out other places like the vent on top or the dipstick tube but I think you would see where it was coming from. It would have to be the drain back hole in the pump or possibly dirt on the converter hub that washed away for it to stop leaking. Anyways it is always recommended never to overfill the tranny so I won't say that can't cause it.After this many years of mechanicing I never discount anything. Glad it stopped and hope it stays not leaking. V V

**VetteVet** · 01-15-2006, 10:50 PM

If it's any consolation which it isn't My 67 had a 700r4 in it which was built and installed by the previous owner and it had the same problem. He had it pulled and new seal installed three times and it still leaked. After I bought it I had the trans out and had a shop rebuild the front pump and they found a bad bearing in the torque converter. They also told me the trans probably wouldn't last much longer although it was working fine except for the leak. I had the choice of replacing all of it or installing a th 350. Wish they had told me all this before they rebuilt the pump and pressure checked the converter.
My 700 is one of the older ones with the 27 spline front pump but it was plenty strong. I just wish I knew what caused the front seal to leak. I have read about the converter bushing moving out and pushing the seal out so I checked that and it was oK. the front drainback hole was drilled bigger too. I read on one trans website that the only way to keep them from leaking was to rebuild the pump and get a new converter. If I can find a 27 spline converter I might put it in, but for now I'm going to run the th350.
Sorry for the long saga. V V

01-09-2006, 05:55 PM	#1
Dakota Kid Registered User Join Date: Feb 2003 Posts: 36	Freshly rebuilt 700R4- Leaking Input Shaft Seal Just had my 700R4 rebuilt by a local shop. I pulled and installed the tranny, not fun at all in my book. I haven't driven it ten miles yet. Didn't have leak until today, I warmed it up and was going to take it to the trans shop to make sure my TV cable adjustments are OK. I noticed a small puddle, and after taking the flywheel cover off, it looks like the input seal is leaking. What could have happened?? I slid the convertor on, made sure it was seated. It rotated freely when not bolted to the flywheel. I wondering what I should do, a brand new seal shoulnd't be leaking, and I don't think I could have screwed anything up. Suggestions?? Thanks DK

01-09-2006, 05:57 PM	#2
bglad420 Registered User Join Date: Dec 2005 Location: Bellingham, WA Posts: 167	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal Did you put the tranny and coverter in as one unit???? cuz if you bolted the converter to the flexplate and then put the tranny up you might have blown the front pump.......Or it might just be the front seal the I put a new tranny in my car, and the seal just went out 2 days later...**** happens(I hope its your front seal) You know what check your dipstick tube make shure the o ring is ok, my blazer liked to leak from their....It drove me CRAZY!!!!!!! Last edited by bglad420; 01-09-2006 at 05:58 PM.

01-09-2006, 08:25 PM	#3
Green Machine Senior Member Join Date: Jul 2004 Location: Estherville, Iowa Posts: 3,371	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal The convertor hub should be lightly greased or at least oiled before putting into the trans. If it was installed dry, it can wipe out the seal before it gets oil. Tranny can also leak between the front pump and the case, or around a front pump bolt. Sorry, but looks like R&R time. __________________ 1968 C10 307 3spd Long Fleet ------ http://67-72chevytrucks.com/vboard/s...d.php?t=201103 1970 C10 305 Super T10 Long Fleet --- http://67-72chevytrucks.com/vboard/s...d.php?t=202285 1971 C20 383 TH350 Dana Posi ----- http://67-72chevytrucks.com/vboard/s...d.php?t=206894 2001 GMC Sierra 1500 C3 6.0

01-10-2006, 01:08 AM	#4
Dakota Kid Registered User Join Date: Feb 2003 Posts: 36	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal Tranny and convertor were put in together, then bolted to the flexplate. Hub was lightly greased when put in. I thought it may have been a pump bolt, but it looks like the input seal. I have checked the dipstick, cooler lines etc. It really wasn't fun to take in/out, and I really don't have the time to do it. I was just getting ready to sell it when the tranny went south, now a grand plus later and here I am where I started. Thanks for the help.

01-10-2006, 09:03 PM	#5
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,703	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal Here's some good reading on the 700r4 http://www.transmissioncenter.net/700R4.htm __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

01-14-2006, 06:19 PM	#6
Dakota Kid Registered User Join Date: Feb 2003 Posts: 36	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal Any chance overfilling the tranny could spit some out the input shaft? I was overfull, now I am just a bit over. Fluid level shows just below the bottom of warm when cold. Started it up today, drove it a bit, and don't seem to have a leak?? WTF?? Just hoping it doesn't pop up again later.

01-15-2006, 09:33 PM	#9
Dakota Kid Registered User Join Date: Feb 2003 Posts: 36	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal Thanks for the input. Sad story, but it is leaking again. Going to have to yank it out again Not real happy, but what can one do?? Should go a bit easier now that I've had it out once.

01-15-2006, 03:05 PM	#10
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,703	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal It might cause fluid to leak out other places like the vent on top or the dipstick tube but I think you would see where it was coming from. It would have to be the drain back hole in the pump or possibly dirt on the converter hub that washed away for it to stop leaking. Anyways it is always recommended never to overfill the tranny so I won't say that can't cause it.After this many years of mechanicing I never discount anything. Glad it stopped and hope it stays not leaking. V V __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

01-15-2006, 10:50 PM	#11
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,703	Re: Freshly rebuilt 700R4- Leaking Input Shaft Seal If it's any consolation which it isn't My 67 had a 700r4 in it which was built and installed by the previous owner and it had the same problem. He had it pulled and new seal installed three times and it still leaked. After I bought it I had the trans out and had a shop rebuild the front pump and they found a bad bearing in the torque converter. They also told me the trans probably wouldn't last much longer although it was working fine except for the leak. I had the choice of replacing all of it or installing a th 350. Wish they had told me all this before they rebuilt the pump and pressure checked the converter. My 700 is one of the older ones with the 27 spline front pump but it was plenty strong. I just wish I knew what caused the front seal to leak. I have read about the converter bushing moving out and pushing the seal out so I checked that and it was oK. the front drainback hole was drilled bigger too. I read on one trans website that the only way to keep them from leaking was to rebuild the pump and get a new converter. If I can find a 27 spline converter I might put it in, but for now I'm going to run the th350. Sorry for the long saga. V V __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.



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