How hard is it to change the detent (kickdown) cable transmission seal? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jayschevy · 02-02-2015, 03:45 PM

I have a TH350 transmission in my 71 and I've been noticing that I have a fluid leak. I was able to jack it up and get under it this weekend to take a good look at it. It looks like the leak is coming from the detent cable that goes in and bolts to the transmission.
My question is, is there a seal in there that I can change out to stop the leak? If so, how hard is it? It only has one bolt holding it in and not knowing much about it, I was worried that I may pull something out that I couldn't get back in.
Any help would be appreciated. Thanks

octanejunkie · 02-02-2015, 06:56 PM

Quote:

Originally Posted by Jayschevy

I have a TH350 transmission in my 71 and I've been noticing that I have a fluid leak. I was able to jack it up and get under it this weekend to take a good look at it. It looks like the leak is coming from the detent cable that goes in and bolts to the transmission.
My question is, is there a seal in there that I can change out to stop the leak? If so, how hard is it? It only has one bolt holding it in and not knowing much about it, I was worried that I may pull something out that I couldn't get back in.
Any help would be appreciated. Thanks

There should be an o-ring seal on the kickdown cable. You can open that one bolt and pull the cable boss (trans tube) out of the trans to check.
RTV silicone can be used to seal the trans tube to the trans body upon reinstallation.

These Lokar instructions might help you

**MikeB** · 02-05-2015, 11:36 AM

The key diagram is Figure 4 on the second page of those Lokar instructions. The TV wire on your trans may not stick out that far, but feel free to pull on it to disconnect/connect it from/to the cable. It's spring loaded and will move 1" or so.

This may also help:

I'm not sure there are any parts you can replace, so you may have to buy a new cable for your year & model truck. I've used this cable on a 69 C10 with a 307 and TH350. http://www.bulkpart.com/2/product/35...is/T44450.html

Bad picture I know. You can probably get it at a local parts store.

**MikeB** · 02-05-2015, 11:45 AM

Here you can see the wire pulls against the throttle valve lever. That's a Lokar cable.

GASoline71 · 02-05-2015, 06:08 PM

There is no "TV" cable for a TH350. Just a kickdown "detent" cable.

The o-ring can be replaced but you have to disconnect the cable from the wire inside the tranny. The wire inside the tranny is bent in a square "S" shape and it hooks into the hole in the kickdown cable. Once you take the bolt out and pull the cable housing up it will be obvious how it's connected.

When you pull that cable housing up, be prepared for some tranny fluid to leak out of there.

Gary

motornut · 02-06-2015, 11:06 AM

Quote:

Originally Posted by GASoline71

There is no "TV" cable for a TH350. Just a kickdown "detent" cable.

The o-ring can be replaced but you have to disconnect the cable from the wire inside the tranny. The wire inside the tranny is bent in a square "S" shape and it hooks into the hole in the kickdown cable. Once you take the bolt out and pull the cable housing up it will be obvious how it's connected.

When you pull that cable housing up, be prepared for some tranny fluid to leak out of there.

Gary

thats how i did it

**MikeB** · 02-06-2015, 12:28 PM

Quote:

Originally Posted by GASoline71

There is no "TV" cable for a TH350. Just a kickdown "detent" cable.
Gary

I stand corrected. Funny because I just went through the valve body on a TH350, and connected a Lokar detent cable. So I know it's a detent valve, not a TV valve as on 700R4 and 2004R. I think the problem is I've heard the term "TV cable" too much.

GASoline71 · 02-06-2015, 01:06 PM

LOL... Sorry Mike... didn't mean to come across as "correcting".

Hard to put voice tone and feeling into words on a computer.

Gary

**MikeB** · 02-06-2015, 04:08 PM

Quote:

Originally Posted by GASoline71

LOL... Sorry Mike... didn't mean to come across as "correcting".

Hard to put voice tone and feeling into words on a computer.

Gary

Well, you did come across that way, just a little. But I have tissues here on my desk.

octanejunkie · 02-06-2015, 04:10 PM

Hug it out fellas... no one lost an eye this time. It's all good

Marv D · 02-06-2015, 04:39 PM

Jay,
key here is you have to pull the trans pan, so get the o-ring for the kick-down, one for the dipstick tube and a new pan gasket and a filter. If your going to this trouble.... do it all and be done with it.

The TH350 has a couple of different dipstick tube seals. If you want to be prepared just pick up both the O-ring and the bushing type (think the bushing type is only for the metric cases,, but maybe not). Besides, they are cheap enough so just get all possibilities to save the gas of running back to the parts house.

just a suggestion

BillyJoe03 · 06-18-2017, 01:28 PM

I'm looking for the original transmission kickdown cable for my 1971 Chevy truck 350 hydromatic I had someone work on it and replaced it why I don't know does anybody know where I can find the original one that has the orange plastic that ties into the carburetor that is the correct one?

cg285 · 06-19-2017, 11:54 AM

i don't believe the original cable was any other color than black

02-02-2015, 03:45 PM	#1
Jayschevy Registered User Join Date: May 2012 Location: Eastern, NC Posts: 429	How hard is it to change the detent (kickdown) cable transmission seal? I have a TH350 transmission in my 71 and I've been noticing that I have a fluid leak. I was able to jack it up and get under it this weekend to take a good look at it. It looks like the leak is coming from the detent cable that goes in and bolts to the transmission. My question is, is there a seal in there that I can change out to stop the leak? If so, how hard is it? It only has one bolt holding it in and not knowing much about it, I was worried that I may pull something out that I couldn't get back in. Any help would be appreciated. Thanks

02-05-2015, 11:36 AM	#3
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,430	Re: How hard is it to change the detent (kickdown) cable transmission seal? The key diagram is Figure 4 on the second page of those Lokar instructions. The TV wire on your trans may not stick out that far, but feel free to pull on it to disconnect/connect it from/to the cable. It's spring loaded and will move 1" or so. This may also help: I'm not sure there are any parts you can replace, so you may have to buy a new cable for your year & model truck. I've used this cable on a 69 C10 with a 307 and TH350. http://www.bulkpart.com/2/product/35...is/T44450.html Bad picture I know. You can probably get it at a local parts store. __________________ Mike 1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

02-05-2015, 11:45 AM	#4
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,430	Re: How hard is it to change the detent (kickdown) cable transmission seal? Here you can see the wire pulls against the throttle valve lever. That's a Lokar cable. __________________ Mike 1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

02-06-2015, 04:10 PM	#10
octanejunkie Registered User Join Date: Jan 2015 Location: Santa Monica Posts: 264	Re: How hard is it to change the detent (kickdown) cable transmission seal? Hug it out fellas... no one lost an eye this time. It's all good __________________ Déjà vu. It's that feeling you get when you hit your thumb with the hammer a second time '59 Chevy 3100 Stepside

02-06-2015, 04:39 PM	#11
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: How hard is it to change the detent (kickdown) cable transmission seal? Jay, key here is you have to pull the trans pan, so get the o-ring for the kick-down, one for the dipstick tube and a new pan gasket and a filter. If your going to this trouble.... do it all and be done with it. The TH350 has a couple of different dipstick tube seals. If you want to be prepared just pick up both the O-ring and the bushing type (think the bushing type is only for the metric cases,, but maybe not). Besides, they are cheap enough so just get all possibilities to save the gas of running back to the parts house. just a suggestion __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

06-18-2017, 01:28 PM	#12
BillyJoe03 Registered User Join Date: May 2017 Location: San Antonio TX Posts: 1	Re: How hard is it to change the detent (kickdown) cable transmission seal? I'm looking for the original transmission kickdown cable for my 1971 Chevy truck 350 hydromatic I had someone work on it and replaced it why I don't know does anybody know where I can find the original one that has the orange plastic that ties into the carburetor that is the correct one?

06-19-2017, 11:54 AM	#13
cg285 Registered User Join Date: Aug 2013 Location: sumterville, florida Posts: 914	Re: How hard is it to change the detent (kickdown) cable transmission seal? i don't believe the original cable was any other color than black



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