Looking for a measurement TH350 cable.
 

Can anyone measure how much travel the detent cable (Kick down cable) has? Basically from the bracket to the end of the cable fully extended. Blue arrow to blue arrow at full throttle.

I have just replaced my TH400 with a TH350 and I am unable to get the throttle to open completely with the cable hooked up. I have what appears to be the common Chevrolet small block bracket that bolts to the last 2 bolt on the intake manifold. I have lifted the tab on the new cable and adjusted the cable as far forward as it will go. This only lets the secondaries on the Qjet open about 30%.

I'm starting to believe that maybe the transmission end of the kick down may be the problem. If I knew how much the cable should be able to move I can compare that to mine before I start pulling things apart.

I've got a couple of hours searching for the solution but all the different factory brackets seem to to put the cable at the same distance on the manifold. With all OEM components there isn't any reason I can see why this isn't working properly. Last photo is the bracket style I have installed.

Re: Looking for a measurement TH350 cable.
 

Obviously our throttle linkage is different, but maybe you can find a reference point.(coil bracket, valve cover bolt?)

1st pic is measured from center of TV bolt.
2nd pic is wot. 8 inches.
3rd pic is at idle, about 6 and 3 quarters of an inch.
4th pic is secondary plates wide open. (bad pic I know):lol:

Re: Looking for a measurement TH350 cable.
 

there should be a tab you can pull up and adjust the cable length that travels through on the square part that is next to bracket.

Re: Looking for a measurement TH350 cable.
 

never mind I see you have tried that already

Re: Looking for a measurement TH350 cable.
 

Thank you for taking the time to do this I appreciate it. It looks like your getting 1 and 3/4 inch of movement from the cable.

Re: Looking for a measurement TH350 cable.
 

Hope it helps. ;)

Re: Looking for a measurement TH350 cable.
 

Yes. I have the spring part of the adjustment mechanism squeezed together as tight as it can go. And still not enough movement to get full throttle.

Re: Looking for a measurement TH350 cable.
 

When it quits pouring rain I will go out and see what I can figure out.

Re: Looking for a measurement TH350 cable.
 

Th350 is a detent cable only, not a pressure feed cable for line pressure like a 700R4.

Take detent cable off the carb and slowly pull it out, you should feel the lever in the trans push the valve in, then a little more pressure to get to the last cable out position.
If you can feel the valve move, the cable is most likely not installed correctly inside the trans.

Have someone hold the accelerator fully open and pull the detent cable fully out.

You should be able to slip the end of the detent cable onto the pin on the carb throttle plate.

I have seen folk not put the square end of the cable fully into the square hole in the bracket...it must fully seat inside the bracket.

I have also seen the inner cable out too far in the square connector base....push on the tab on side of the square block and push the inner cable towards the front. this should let you now connect the detent cable...

To set it...have someone push gas pedal to floor, then pull outer detent cable backwards to remove all slack in the inner cable.

Pics of your setup will help

Re: Looking for a measurement TH350 cable.
 

The cable is firmly seated in the bracket.
I cannot pull the cable out far enough to get the end to go on to the pin on the throttle arm with the cable in the bracket.
The first 2 photos I posted are of my truck.
I don't understand what you have written here.
"you should feel the lever in the trans push the valve in, then a little more pressure to get to the last cable out position.
If you can feel the valve move, the cable is most likely not installed correctly inside the trans."

Re: Looking for a measurement TH350 cable.
 

"you should feel the lever in the trans push the valve in, then a little more pressure to get to the last cable out position.
If you can feel the valve move, the cable is most likely not installed correctly inside the trans." refers to a check you can do to make sure the cable and linkage inside the trans is not binding up and restricting movement...

I just noticed the carb end of your cable has a simple round attachment end...most TH 350s have a cable that has an elongated slot as per link pic below...perhaps the cable is not the correct one...

These cables come in several different lengths..40" and 42" come to mind...

42 "
https://www.summitracing.com/parts/p...CABEgKmwPD_BwE

40"

https://www.summitracing.com/parts/a...SABEgItHfD_BwE

Re: Looking for a measurement TH350 cable.
 

[QUOTE=AussieinNC;8749390]"you should feel the lever in the trans push the valve in, then a little more pressure to get to the last cable out position.
If you can feel the valve move, the cable is most likely not installed correctly inside the trans." refers to a check you can do to make sure the cable and linkage inside the trans is not binding up and restricting movement...

I just noticed the carb end of your cable has a simple round attachment end...most TH 350s have a cable that has an elongated slot as per link pic below...perhaps the cable is not the correct one...

These cables come in several different lengths..40" and 42" come to mind...
/QUOTE]

I am confused again. This time about the cable end on my detent cable. It has a slot. Is it the incorrect slot? See photo below. The cable seems to be the proper length.

Re: Looking for a measurement TH350 cable.
 

Here are more photos of my cable.

Re: Looking for a measurement TH350 cable.
 

Your throttle cable and trans kick down sure look right to me. Here comes a dumb question. If you undo the trans cable temporary, do you get full throttle? Is there any way the cable bracket is wrong or bolted to far back? I'm not sure if that is even possible.

Re: Looking for a measurement TH350 cable.
 

The carburetor was fully opening prior to the transmission change. When I floor it the kick down cable is taunt and obviously the limiting factor in opening the secondarys
I had driven the truck fairly conservatively for the first 75 miles. Then when I finally opened it up I was thinking "Man this transmission certainly seems slower than the old one!"
After some checking I found out it really was slower but, not for the reason I was thinking of.
I had a friend double check things and the bracket only goes on one way and there doesn't seem to be any other brackets that mount the cable in a noticeably different position in relation to the throttle shaft.
I would like to have my ducks in a row before I have to take it back to the transmission rebuilder.

Re: Looking for a measurement TH350 cable.
 

AussieinNC says the cables come in different lengths. Kinda sounding like yours is to short? That may be the problem. Good luck, let us know what you find out.

Re: Looking for a measurement TH350 cable.
 

The attached pic will show the later location of the detent cable bracket...approx 2" closer to the carb pivot....

I think the trans came out of a later vehicle (or has the later cable installed) making the working length of the cable when mounted in the rear position bracket too short.

I would either locate a later bracket or find the earlier model cable that suits the rear mount bracket.

Hope this helps out

:chevy::chevy::chevy:

Re: Looking for a measurement TH350 cable.
 

Any idea what the bracket pictured came on? In my 2 hours of searching the interweb I didn't run across a bracket like that one. It looks like it would do the trick.
Thank you sir.

Re: Looking for a measurement TH350 cable.
 

Try looking for an 77 -80 era El Camino style bracket that bolts to the two rear Q Jet mounting bolts....see pic, you can see the bracket in the back bolts of the Qjet...

Most wreckers throw these brackets out....making them hard to find...

To be honest, I usually use the bracket you have, cut the mount tab off and use stock metal to mount the bracket where it needs to be...

These brackets and the various methods of mounting makes this seemingly easy task a huge headache....I have actually had many TH350's turn up with the cable just laying on the intake manifold because the owner or mechanic had given up trying to mount it.

You can drive these without the cable connected, you just need to manually downshift to second....

Hope this helps...

Re: Looking for a measurement TH350 cable.
 

I think the later model cables use a rubber boot to seal at the trans. The early models use an O-ring.

Re: Looking for a measurement TH350 cable.
 

Thanks for the lead on make and model. I think the Elkes of those years were G-bodies so that may help widen my search for a donor vehicle.
If all else fails fabing a bracket isn't a problem but it's a 350/350 combo it shouldn't be that hard to just bolt it together. It's not like I'm trying to stuff a OHC Pontiac in a 1952 Ford 4x4 truck. :lol:

Re: Looking for a measurement TH350 cable.
 

Hopefully the lead on the bracket pays out and I don't have to get a new cable.


Thanks everyone for all your time and effort.

Re: Looking for a measurement TH350 cable.
 

I actually had an OHC Cammer in an Aussie Holden way back when...seems like a lifetime ago...heck...it was...

Hope your search bears fruit, but I usually just fab up a bracket to suit...there are aftermarket adjustable brackets available from Summit and Jegs etc...

:chevy::chevy::chevy:

Re: Looking for a measurement TH350 cable.
 

That's cool. I do like me a Cammer motor.

Re: Looking for a measurement TH350 cable.
 

After spending half a day at the u-pull it yard I came home with 4 different brackets. They came off of 83 GMC Caballero (2), a 1995 Van (3), a 79 C10 (4), and a 77 Oldsmobile Cutlass (5).
The photo also shows the one I had installed on the WMB (1) that was incorrect. The brackets are sort of arranged to show the the difference in the detent cable locations. (Blue lines.) The red arrow indicates the bolt hole that the last bolt on the intake manifold would go through. The #5 bracket only bolts to the carburetor back bolts so I was less accurate in placing it.
I initially went with the #5 bracket as I liked the all in one bracket and it was within the range of adjustment for the detent cable. However after I got it cleaned up, painted, and installed I realized that I could only get 90% opening of the secondaries. The angle to the throttle shaft arm was wrong. 90% was much better than before but I real want 100%. So I ended up pulling it off and using the #2 bracket and my original (Original in that it was on the truck when I bought it.) bracket. Now I have full throttle opening and the transmission shifts down nicely.