Detent cable question

[carpart67]

I've got a 1986 GMC 1500 4x4. Its got a turbo 350 auto trans. According to the VIN it was originally a 4bbl 305. The engine is now a 350 with 2 bbl carb.

I want to replace the detent cable for the trans as mine is broken. I ordered a cable from GM but it's not like the one on the truck now. The eyelet, on the trans end of the new cable, that fits over the hook in the transmission has a smaller hole than the original cable. Also the part of the cable housing that seats into transmission is larger in diameter on the new cable than it is on the original cable, and uses a different seal. The engine side of the new cable looks like it would work, but is not identical to the old cable either.

I couldn't seem to get the new cable attached to the transmission but I was being pretty careful with it in case I needed to return it, plus its a miserable spot to get at. I am just wondering if the detent cables for the turbo 350 are a universal fit even if they are cosmetically different? Are the hole diameters for the detent cable the same on all turbo 350 transmissions, or is it possible I was given the wrong cable?

I'm kind of a newb to this gear and I don't want to return the cable if it's correct. Any help would be appreciated.

 

[bucket]

Your '86 probably came stock with a 700r4 overdrive trans, which is probably what your cable is for.

 

[carpart67]

I thought it was the original trans, but it's possible I'm worng. If it's not they must have swapped the cluster as well as mine only has the indicators for P,R,N,D,2,1. Looking at some pictures online the new cable does look like it may be for a 700R4. If I posted a picture of the new cable would someone be able to tell me if it is indeed for a 700R4?

The new cable I was given looks like this

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My old one looks like this, but with the same plastic clip on the throttle side as the new one

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[HotRodPC]

The Th350 came in both of those styles depending on the year model and application. But that bottom style was NOT used on 700r4 at all. So it's probably safe to say your truck was converted to Th350. You could probably make either style work for a Th350 since both were used OEM, but if the connector to the trans is wrong, like smaller than your original, then you'll have a leak there. Anyway to take the old cable with you to the auto parts store?

 

[carpart67]

The Th350 came in both of those styles depending on the year model and application. But that bottom style was NOT used on 700r4 at all. So it's probably safe to say your truck was converted to Th350. You could probably make either style work for a Th350 since both were used OEM, but if the connector to the trans is wrong, like smaller than your original, then you'll have a leak there. Anyway to take the old cable with you to the auto parts store?

I'm a bit confused now. My original cable is the bottom one ,that was never used on a 700R4, so why does that mean my truck was likely converted? Is it because the newer cable style (top picture) would have been used for both th350 and 700R4 in that year?

The connector on the the trans side where the cable seats into the transmission is larger on the new cable. I couldn't seem to fit it into the trans at all.

I probably could take the old cable to a parts store, but I live in a small, rural town in Canada. Usually if the computer doesn't give them the correct part you're SOL as they have nothing in stock for you to compare with and know very little about vehicles that are 10 or more years old. Even the GM dealership didn't have the cable in stock.

Thanks for the replies guys

 

[Jims86]

I have always seen the bottom pic on the 350's

 

[89Suburban]

Check your RPO codes on the glove box so we know what trans came with it.

 

[bucket]

I'm a bit confused now. My original cable is the bottom one ,that was never used on a 700R4, so why does that mean my truck was likely converted? Is it because the newer cable style (top picture) would have been used for both th350 and 700R4 in that year?

The connector on the the trans side where the cable seats into the transmission is larger on the new cable. I couldn't seem to fit it into the trans at all.

I probably could take the old cable to a parts store, but I live in a small, rural town in Canada. Usually if the computer doesn't give them the correct part you're SOL as they have nothing in stock for you to compare with and know very little about vehicles that are 10 or more years old. Even the GM dealership didn't have the cable in stock.

Thanks for the replies guys

It would have been swapped in with the trans, along with the gear indicator on the cluster. Or it came stock to begin with. The 80's th350 cables had the modern clip-on style end on them like the 700r4 cables. An older (and more common) style th350 cable would probably work too. Use the end of your current cable as a retainer on the stud.

 

[carpart67]

Check your RPO codes on the glove box so we know what trans came with it.

I'm new to this, how do I do that?

 

[89Suburban]

I'm new to this, how do I do that?

There should be a label in the glove box with codes on it. You can check the codes in the reference library here or post a pic and we can help.

 

[carpart67]

Label is there, unfortunately it does not match the VIN of the truck lol. Hard to say if the glove box/door is original. Looks like this truck was quite a piece together. Things rot up pretty quick around here so it's common for a truck to be made up of several trucks lol.

I should be able to order a cable like the bottom one pictured on ebay or another online source if I can't find one locally shouldn't I?

 

[carpart67]

Just an update. I was able to crimp a new eyelet on the carb side of the old cable. Took it for a quick test drive and the trans will down shift when I tramp it, it will also hold the gears longer on a hard take off. Seems to work.

Any reason why I shouldn't leave it like this until I get another cable? Any way it could cause problems?

 

[89Suburban]

Just an update. I was able to crimp a new eyelet on the carb side of the old cable. Took it for a quick test drive and the trans will down shift when I tramp it, it will also hold the gears longer on a hard take off. Seems to work.

Any reason why I shouldn't leave it like this until I get another cable? Any way it could cause problems?

IMO it's better than nothing. Did you have luck tracking down a cable?

 

[HotRodPC]

Sounds like you got it working just fine. You say Detent cable, so I'm assuming Th350? The Th350 is nowhere near as critical as the 700r4 TV cable, so if the trans is working like you like it, then all is well and I'd call it a permanent fix. If it's dragging the shift points out to long now, then adjust the cable to be a hair shorter until you get it where you like it if you don't like where it's at now. If it works, it works, no reason to replace the cable.

Now if i was doing a trans rebuild, then I'd probably go ahead and buy a new cable, but otherwise, don't fix it if it ain't broke.