Checking my mechanic's 700r4 install

[the_nutt]

Hey guys,

My '72 C10 has been in the shop for a bit getting a 700r4 swapped in place of a shredded TH350. They did a good job, the work is warrantied, and I'm not trying to look for problems, but I'm new to some of these intricacies and would really appreciate some experienced feedback.

When I dropped off the truck I also provided the shop with links to TV cable alignment carb brackets, lockup wiring kits, etc. He said their transmission builder (on the job for ~20 years) was going to do the lockup via vacuum, and assured me they would set the TV cable correctly.

Based on the picture below, it looks to me like the TV cable is hooked up to the stock Edelebrock throttle/TV cable bracket. I was under the impression an adapter like the one here at Summit (and pictured below) was A REQUIREMENT for a swapped 700r4.

I drove the truck about 5 miles total after leaving the shop, and at some points it will "fall into neutral" while driving; usually when slightly letting up on the gas after reaching cruising speed ~45mph. Mechanic thinks its because they tried to re-use the original shift linkage, and new Lokar adjustable linkage is on the way.. but I'm afraid that's a sign of the TV cable being incorrectly adjusted.

I know running/driving an improperly adjusted TV cable is a really bad idea, so the truck is parked until the shop goes back to the shop for the Lokar linkage to be installed.

Any feedback from y'all this weekend before I take it back into the shop would be much, much appreciated. Thanks in advance!

[Lowenuf]

the tranny shouldn't be dropping to neutral on throttle release.

the 700r4 should remove itself from "convertor lockup", however, i think you received some ill information. the 700r4 requires an electrical pulse to activate the pressure sensor for total convertor lock up.. see bowler transmissions..
http://bowlertransmissions.com/p/103...control-module

sounds to me like not only is the TV cable not correctly adjusted, that also you may be having fluid pressure issues in the valve body...

here are some pics of my TV cable attached to a 600cfm Holley...







if your TV cable isn't properly adjusted, you can burn the tranny up fairley fast....

you must also make sure that a "lockable" convertor was used, there is a non-lockable model available for using the tranny as a straight 4-speed auto....

[Bigdav160]

When you say "fall into neutral" does that mean it's coasting (instead of engine braking) or do you mean it won't accelerate again until you slow down to another gear range?

The forward clutch drives through a one-way sprag in 1-2-3 so no engine braking until 4. even then at a .75:1 gear ratio it's hard to tell. Manual third should have engine braking because the input clutch holds the sprag.

I'm no expert on carb linkage but it does look wrong. Eventually it will burn the clutches because it doesn't allow enough pressure rise.

[Lowenuf]

it also looks like your TV cable isn't adjusted correctly, simply because of the ampount of slack i see in the cable, and the excess sticking beyond the the "stop" (baffled by the use of that piece)...

A properly adjusted cable requires that you open the accelerator cable to full throttle, the the TV cable adjusted to that setting......

if done correctly, you shouldn't have much TV cable protruding beyond the throttle plate connecting point....

[Lowenuf]

and yes, the Turbo350 linkage will not adjust correctly to operate the 700r4....

at least not on the tranny end...... there is a retro fit adapter made to do that operation

[Bigdav160]

That appears to be a common "universal" TV cable available at any parts place.

[Coach]

You definitely have too much slack in the TV Cable. I had my 700r4 rebuilt last April by a very reputable transmission shop the specialized in classic cars, trucks, etc...and very familiar with the 700r4 issues. The best thing to do is to have the Bowtie Overdrive TV made EZ cable kit installed. It will correctly set the cable, geometry, line pressure, etc... As far as lock up is concerned, go with the Bowler Transmission lock up kit. It will delay lock up for 8 seconds in Overdrive and also will come out of lock up when the brakes are applied, give you 8 more seconds to get up to highway speed and then lock up again. Good luck, hope it works out.

[the_nutt]

Originally Posted by Lowenuf

the tranny shouldn't be dropping to neutral on throttle release.

the 700r4 should remove itself from "convertor lockup", however, i think you received some ill information. the 700r4 requires an electrical pulse to activate the pressure sensor for total convertor lock up.. see bowler transmissions..
http://bowlertransmissions.com/p/103...control-module

sounds to me like not only is the TV cable not correctly adjusted, that also you may be having fluid pressure issues in the valve body...

if your TV cable isn't properly adjusted, you can burn the tranny up fairley fast....

you must also make sure that a "lockable" convertor was used, there is a non-lockable model available for using the tranny as a straight 4-speed auto....

Re: "dropping into neutral" - after I let off the gas pedal there is no engine braking happening, and if I give it gas again the engine just revs, as if its in neutral. I then had to wiggle the column shifter to get it to "find" drive again. And that's why I immediately parked it because I know something is amiss.

So are you saying that a lockup kit is REQUIRED for proper 4-speed + lock-up operation, and that just a "shop mod" cannot be efficient? Am I correct in my thinking that the expected operation should be P-R-N-OD-D-2-1, allowing me to run in D on surface streets (without lock-up), and then I should feel 1st, 2nd, 3rd, 4th, then lock-up when getting on the highway?

Is there a way for me to get under the truck and tell whether the torque converter is a "lockable" one or not?

Originally Posted by Bigdav160

When you say "fall into neutral" does that mean it's coasting (instead of engine braking) or do you mean it won't accelerate again until you slow down to another gear range?

The forward clutch drives through a one-way sprag in 1-2-3 so no engine braking until 4. even then at a .75:1 gear ratio it's hard to tell. Manual third should have engine braking because the input clutch holds the sprag.

I'm no expert on carb linkage but it does look wrong. Eventually it will burn the clutches because it doesn't allow enough pressure rise.

Re: "dropping into neutral" - after I let off the gas pedal I'm just coasting (no engine braking happening), AND if I give it gas again the engine just revs, as if its in neutral. I then had to wiggle the column shifter to get it to "find" drive again. And that's why I immediately parked it because I know something is amiss.

Originally Posted by Coach

You definitely have too much slack in the TV Cable. I had my 700r4 rebuilt last April by a very reputable transmission shop the specialized in classic cars, trucks, etc...and very familiar with the 700r4 issues. The best thing to do is to have the Bowtie Overdrive TV made EZ cable kit installed. It will correctly set the cable, geometry, line pressure, etc... As far as lock up is concerned, go with the Bowler Transmission lock up kit. It will delay lock up for 8 seconds in Overdrive and also will come out of lock up when the brakes are applied, give you 8 more seconds to get up to highway speed and then lock up again. Good luck, hope it works out.

As I asked above, are you saying that a lockup kit is REQUIRED for proper 4-speed + lock-up operation, and that just a "shop mod" cannot be efficient? Am I correct in my thinking that the expected operation should be P-R-N-OD-D-2-1, allowing me to run in D on surface streets (without lock-up), and then I should feel 1st, 2nd, 3rd, 4th, then lock-up when getting on the highway?


Thank you all again for the help. I'm usually able to stay on top of this kind of stuff, but there's so much different information floating around about these transmissions, and the confident attitude the shop started with is starting to seem like a ruse.

Any other thoughts regarding things I can check, pictures I can post, questions to ask the shop, or parts/kits that should be REQUIRED for this swap, please let me know.

Cheers!

[Coach]

If you read up on the 700r4 lock up using vacuum, people complain that it is inconsistent and will cycle in and out of lock up while cruising on the freeway. The most reliable way is the lock up kit that delays for 8 seconds and only disengages when the brakes are applied. You are correct, street driving can be done in 3rd gear (D) and then shift to 4th gear (OD) on the freeway, that is how I drive my truck and was the recommendation from my tranny mechanic.

[Lowenuf]

if the TV cable is adjusted correctly, you can run without a converter lock-up option, however, freeway driving will suffer a bit....

you are correct, the gear selection is P-R-N-OD-3-2-1 you can, and i do operate my truck around town in the 3rd gear position to alleviate the converter from engaging at lower speeds when the tranny would want to shift into 4th gear....

nothing wrong with running in 3rd, but cooling through the radiator and possibly an external cooler is a must.

like i said, converter lock up requires an electrical signal, the 700r4 converter will not lock up with a good "vacuum" feature of any kind, that i am aware of.....

your cable being out of adjustment is why your tranny has no braking/acceleration, fluid control is non-existent...

[Lowenuf]

http://www.700r4.com/tech/tc_article/

[Eddie H.]

Looks like it's time to get a new mechanic. The TV cable is not setup correctly the way they have it. The adapter from Summit works ok, but I prefer the Bowtie Overdrive kit.

[the_nutt]

Originally Posted by Coach

If you read up on the 700r4 lock up using vacuum, people complain that it is inconsistent and will cycle in and out of lock up while cruising on the freeway. The most reliable way is the lock up kit that delays for 8 seconds and only disengages when the brakes are applied. You are correct, street driving can be done in 3rd gear (D) and then shift to 4th gear (OD) on the freeway, that is how I drive my truck and was the recommendation from my tranny mechanic.

So the Bowler lockup kit engages lockup 8 seconds into 4th, even if I'm on the gas? I was under the impression that lockup (OD) should only be engaging when its not "under load", i.e. maintaining speed, not gaining speed.

Out of curiosity, is there a reason you prefer the Bowler kit vs. this lockup kit from TCI? How essential is having a manual lockup override?

Originally Posted by Lowenuf

You are correct, the gear selection is P-R-N-OD-3-2-1. You can, and i do operate my truck around town in the 3rd gear position to alleviate the converter from engaging at lower speeds when the tranny would want to shift into 4th gear....

Nothing wrong with running in 3rd, but cooling through the radiator and possibly an external cooler is a must.

Your cable being out of adjustment is why your tranny has no braking/acceleration, fluid control is non-existent...

While the radiator is older, I did have them install an external transmission cooler as well.


Thank you all again for confirming my assumptions/fears. I just want to go back in there backed up with as much information as possible, and didn't want to fly off half cocked if I ended up assuming wrong.

[the_nutt]

Originally Posted by Eddie H.

Looks like it's time to get a new mechanic. The TV cable is not setup correctly the way they have it. The adapter from Summit works ok, but I prefer the Bowtie Overdrive kit.

I agree. I'm not going to take new things to them, but I am going to make them do the work I paid for correctly before we part ways.

Since the transmission is warrantied, I know that if I personally install a different lockup kit and TV cable assembly they would blame any future issues on that and most likely refuse to honor their warranty.

[Lowenuf]

The Bowler is the easiest to install, and in my opinion, the most reliable.

Yes, it engages lock up 8 seconds after shifting into 4th, but only if at a cruzing speed, not under a throttle load.....

[72_K10_Vegas]

Couple of items:

Vacuum switch is a good install but HAS to be installed to a ported manifold vacuum source. (vacuum only when throttle is open) and you should really have a vacuum valve installed as well.

This has to be used in conjunction with the brake switch and to the 4th gear pressure switch which activates lockup. I have also added a contact in series that is tied into the speed output (2k PPM) of my Dakota Gauge computer. This keeps the system from engaging to soon as the other Gents have written about.

Definitely not hacking on a mech that has 20 years experience. but it kind of sounds like that, besides problematic TV setup, if you are using vacuum for lockup, it is not hooked to the right port.

[72_K10_Vegas]

BTW,
Forgot to add,

Senior moment from a junior member?!

I am with Eddie. BowTie is great. Their website has tons of good info.

[diggerbob]

Edelbrock carbs (with the exception of some of their Quadrajets) do not have the proper linkage geometry to run a 700R without some mods to the linkage using something like the Bowtie adaptor. I put the Bowtie linkage mod on mine when I had my old Edelbrock and it worked fine with an old junkyard 700R for years. When I put a later model Qjet on, the geometry of the carb was correct for a 700r so it needed no modification. You should check the engine/transmission board and look especially for posts by "Clinebarger". He is a professional transmission builder and knows a lot about fitting these transmissions to older trucks.

[the_nutt]

Originally Posted by diggerbob

Edelbrock carbs (with the exception of some of their Quadrajets) do not have the proper linkage geometry to run a 700R without some mods to the linkage using something like the Bowtie adaptor. I put the Bowtie linkage mod on mine when I had my old Edelbrock and it worked fine with an old junkyard 700R for years. When I put a later model Qjet on, the geometry of the carb was correct for a 700r so it needed no modification. You should check the engine/transmission board and look especially for posts by "Clinebarger". He is a professional transmission builder and knows a lot about fitting these transmissions to older trucks.

Excellent, thank you. I'll look him up.



So, is the consensus:
1) The TV cable is currently not properly adjusted, causing the weird shifting/neutral action while driving

2) In order for proper TV cable adjustment, I need (at the very least) an aftermarket bracket that attaches to the carb.
- Is an entire TV kit necessary, or will the bracket + the current generic TV cable be sufficient?

3) The current vacuum-only lockup method is both inconsistent, and possibly even not configured correctly. To correct this I need an aftermarket electronic lockup kit, preferably from Bowler.


Sound about right?

[Bigdav160]

Originally Posted by the_nutt

Excellent, thank you. I'll look him up.



So, is the consensus:
1) The TV cable is currently not properly adjusted, causing the weird shifting/neutral action while driving

Possibly but not necessarily. While the throttle valve controls the pressure that holds the clutches and band it also tries to keep the transmission downshifted. Lifting of the gas pedal should cause the transmission to upshift. You could have the valve sticking in the valve body (common)

Originally Posted by the_nutt

2) In order for proper TV cable adjustment, I need (at the very least) an aftermarket bracket that attaches to the carb.
- Is an entire TV kit necessary, or will the bracket + the current generic TV cable be sufficient?

Yes to the bracket. The cable should be OK if adjusted correctly

Originally Posted by the_nutt

3) The current vacuum-only lockup method is both inconsistent, and possibly even not configured correctly. To correct this I need an aftermarket electronic lockup kit, preferably from Bowler.


Sound about right?

There's several ways to do the lockup correctly. Having the lockup function prevents the fluid from overheating while in OD.

[hamjet]

http://www.cpttransmission.com/tech_tvcable.htmhttp://www.cpttransmission.com/Files/tec2.jpghttp://www.tvmadeez.com/article/index.htmlhttp://67-72chevytrucks.com/vboard/s...d.php?t=466933 Here are 4 good reads to maybe help you ouy some.. PS, you should find a better spot for the throttle return spring, it might slip off there,