Shift shaft seal leaking on 700r4?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Randy and Easton

Full Access Member
Joined
Feb 6, 2021
Posts
900
Reaction score
1,302
Location
North Richland Hills, Texas
First Name
Randy
Truck Year
1976
Truck Model
C-10 LWB
Engine Size
350
we agree with @FireTruck1984 . Just take your time. Our first removal tool was defective and had to get on other and it finally bit and the rest was easy. Not a lot of room but doable. I struggled with the first tool for days as it would not bite. Bought our tool and seals on line at www.classic transmission solutions.com and finally called Sandy and he sent a new tool and it worked first time, took 30 minutes and leak gone.

Randy and E
 

Attachments

  • IMG_5568.jpeg
    IMG_5568.jpeg
    128.7 KB · Views: 58
  • IMG_5563.jpeg
    IMG_5563.jpeg
    173.4 KB · Views: 57
  • IMG_5562.jpeg
    IMG_5562.jpeg
    83.9 KB · Views: 66
  • IMG_5561.jpeg
    IMG_5561.jpeg
    92.1 KB · Views: 65

PhotonFanatic

Full Access Member
Joined
Aug 6, 2022
Posts
229
Reaction score
166
Location
Arlen, TX
First Name
Wilhelm
Truck Year
1987
Truck Model
Silverado
Engine Size
5.7
I've decided to let the transmission shop handle it, and they said something I wanted to ask about.

Is there any other reason it could be leaking from that hole? Or could it only be the shift shaft seal? The transmission shop said they couldn't give a price unless they inspected it for other reasons it could be leaking. So I wanted to know if it's possible that there's another reason it's leaking out of the shift-linkage hole.

Thanks all!
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,435
Reaction score
5,558
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I've decided to let the transmission shop handle it, and they said something I wanted to ask about.

Is there any other reason it could be leaking from that hole? Or could it only be the shift shaft seal? The transmission shop said they couldn't give a price unless they inspected it for other reasons it could be leaking. So I wanted to know if it's possible that there's another reason it's leaking out of the shift-linkage hole.

Thanks all!
Could have a plugged vent that is allowing pressure to build in the case, but highly unlikely. Could have a worn shaft that is letting it leak, but again... highly unlikely.
 

PhotonFanatic

Full Access Member
Joined
Aug 6, 2022
Posts
229
Reaction score
166
Location
Arlen, TX
First Name
Wilhelm
Truck Year
1987
Truck Model
Silverado
Engine Size
5.7
Could have a plugged vent that is allowing pressure to build in the case, but highly unlikely. Could have a worn shaft that is letting it leak, but again... highly unlikely.

I wonder if they'll charge a bunch of money to inspect these things. Trying to make sure it's not a common tactic to make more money. I'd be fine with it, if it's legitimate. But some mechanics have the same kinds of ideas that the stealerships have.
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 3, 2023
Posts
403
Reaction score
834
Location
Las Vegas
First Name
Nick
Truck Year
1987
Truck Model
R10
Engine Size
350
I wonder if they'll charge a bunch of money to inspect these things. Trying to make sure it's not a common tactic to make more money. I'd be fine with it, if it's legitimate. But some mechanics have the same kinds of ideas that the stealerships have.
Do it yourself and you wont have to worry about it. And no, there's no reason it would be leaking beyond a worn seal or worn shaft. The seal is a dollar and shaft two to five dollars. Its a easy job and takes only an hour, assuming you drop the pan to do it.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,435
Reaction score
5,558
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I wonder if they'll charge a bunch of money to inspect these things. Trying to make sure it's not a common tactic to make more money. I'd be fine with it, if it's legitimate. But some mechanics have the same kinds of ideas that the stealerships have.
Its not really a time eating inspection... you put the air hose on the breather and give it a hit.. if it goes right in without pressurizing the line, then it isn't clogged. For the shaft you just give it a wiggle... the transmission housing is the bushing(and its the far softer material since its aluminum), so that would be where the excessive wear would be unless you have a groove from it riding on the seal(very unlikely since it doesn't move very often). Honestly, they shouldn't charge you more than an hour of shop time plus parts.

As Nick said, that's like $10 in parts(tops) and and hour of shop time.. so maybe $100? Plus $30 in fluid if they drop the pan.. which I feel they shouldn't unless they find a big groove in the shaft when they pop the seal out.

Or do it yourself in your driveway for $30 and 10 minutes of your time. You can buy the kits online for that and they usually come with the seal, seal removal tool, and seal driver to do it in the vehicle.

Here's one with everything you need and a genuine Timken seal for $25.. Prime one-day shipping too, so you could have it in your hand tomorrow if you order it today.
https://www.amazon.com/dp/B07SJX1BCN/
 

PhotonFanatic

Full Access Member
Joined
Aug 6, 2022
Posts
229
Reaction score
166
Location
Arlen, TX
First Name
Wilhelm
Truck Year
1987
Truck Model
Silverado
Engine Size
5.7
Do it yourself and you wont have to worry about it. And no, there's no reason it would be leaking beyond a worn seal or worn shaft. The seal is a dollar and shaft two to five dollars. Its a easy job and takes only an hour, assuming you drop the pan to do it.

I would if I had the transmission out. But at this point I'm tired of grubbing around under there lol. Been working on the truck fairly regularly for about 6 months and I'm reaching that phase where the hobby is wearing thin and you take a 3 month break.

I might try it (with trans in truck) if I was certain there was a ton of room to work once you got the pan off. But from your video it looked like a tight squeeze.

Its not really a time eating inspection... you put the air hose on the breather and give it a hit.. if it goes right in without pressurizing the line, then it isn't clogged. For the shaft you just give it a wiggle... the transmission housing is the bushing(and its the far softer material since its aluminum), so that would be where the excessive wear would be unless you have a groove from it riding on the seal(very unlikely since it doesn't move very often). Honestly, they shouldn't charge you more than an hour of shop time plus parts.

As Nick said, that's like $10 in parts(tops) and and hour of shop time.. so maybe $100? Plus $30 in fluid if they drop the pan.. which I feel they shouldn't unless they find a big groove in the shaft when they pop the seal out.

Or do it yourself in your driveway for $30 and 10 minutes of your time. You can buy the kits online for that and they usually come with the seal, seal removal tool, and seal driver to do it in the vehicle.

Here's one with everything you need and a genuine Timken seal for $25.. Prime one-day shipping too, so you could have it in your hand tomorrow if you order it today.
https://www.amazon.com/dp/B07SJX1BCN/

That's the kit I bought and I couldn't get it outta there. It just wouldn't bite into the seal. Even had a buddy come try so I could verify it wasn't just me. $100 at the shop doesn't sound bad at all to get rid of this pita. Wish all the trips to the shop over the years were that cheap.

I did look at dropping the cross member so I could hammer the tool in like all the videos show, but the distance the distributor can travel puts the exhaust pipe in front of the hole once you tilt it down.

Thanks to all for the help! As long as I gave it the old college try I'm satisfied.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,435
Reaction score
5,558
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I would if I had the transmission out. But at this point I'm tired of grubbing around under there lol. Been working on the truck fairly regularly for about 6 months and I'm reaching that phase where the hobby is wearing thin and you take a 3 month break.

I might try it (with trans in truck) if I was certain there was a ton of room to work once you got the pan off. But from your video it looked like a tight squeeze.



That's the kit I bought and I couldn't get it outta there. It just wouldn't bite into the seal. Even had a buddy come try so I could verify it wasn't just me. $100 at the shop doesn't sound bad at all to get rid of this pita. Wish all the trips to the shop over the years were that cheap.

I did look at dropping the cross member so I could hammer the tool in like all the videos show, but the distance the distributor can travel puts the exhaust pipe in front of the hole once you tilt it down.

Thanks to all for the help! As long as I gave it the old college try I'm satisfied.
Pop the cap off the distributor and it should be able to come all the way down below the frame rail. Mine on the TH400 has tons of room right where it sits. I also had to whack it on with a hammer to get it to bite, but it was maybe a 5 minute job.
 

PhotonFanatic

Full Access Member
Joined
Aug 6, 2022
Posts
229
Reaction score
166
Location
Arlen, TX
First Name
Wilhelm
Truck Year
1987
Truck Model
Silverado
Engine Size
5.7
Anyone else have the 700R4? Maybe it's not all that difficult to pull and reinstall the transmission. If it's not really a big job, I might still be interested in fixing it myself. Since there's a few other minor odds and ends I'd take care of at the same time. Looks like there's only about 8 bolts in total, and none up too high.

I have pulled and reinstalled a few transmissions in my day and it was never a big deal. It's easier than many other jobs. Seems like doing an automatic would be easier than a standard. (all I've done is standards to change clutches)
 

NickTransmissions

Supporting Member
Supporting Member
Joined
Aug 3, 2023
Posts
403
Reaction score
834
Location
Las Vegas
First Name
Nick
Truck Year
1987
Truck Model
R10
Engine Size
350
Anyone else have the 700R4? Maybe it's not all that difficult to pull and reinstall the transmission. If it's not really a big job, I might still be interested in fixing it myself. Since there's a few other minor odds and ends I'd take care of at the same time. Looks like there's only about 8 bolts in total, and none up too high.

I have pulled and reinstalled a few transmissions in my day and it was never a big deal. It's easier than many other jobs. Seems like doing an automatic would be easier than a standard. (all I've done is standards to change clutches)
Its easy. If you have done it before, it will be just like riding a bike again in that once you get started it will all come back to you.

When you go back to re-stab it, you must ensure the converter doesnt drift forward on you - that's the biggest risk point you'll face. The second area of concern is the TV cable. If yours is old, replace it. Then make sure you do a pressure test to confirm you have adjusted it correctly once the trans is back in.
 

Latest posts

Forum statistics

Threads
44,005
Posts
947,595
Members
36,066
Latest member
75c10
Top