Just looking for another opinion really. I just collected my car yesterday after it's had the trans rebuilt. The place has been doing gearboxes and axles for over 35 years and he came highly recommended. He's done a few third gens before too.

So the shifts are really firm and there's quite a wait for it to shift through the gears. Like it hangs onto each gear a lot longer than normal. I can also hear a rotational whine that goes up and down with the speed.

Test drove it with him and he said he could sort of hear something but wasn't concerned at all. He also said he sets the cable for firm shifts after a rebuild for line pressure and I can adjust it 1 click back. Or 2 clicks back maximum to soften the changes.

I was like oh right ok and just sort of agreed as he's the expert. I drove the car over 40 miles home and it did drive fine. Sat nicely at 60mph most of the way. But yeah...them shifts are pretty harsh and the gap between the shifts is huge.

 

So what happens when you adjust one click back?

 

Is the Transmission the Original 1987 THM700-R4?

Has the Transmission been modified, or just rebuilt/ improved some?

 

I havnt touched it yet. I drove it home and its just sat on the driveway. I will take it out today though.

It's the cars 700R4 yeah. He's put Z-Pak clutches in he said as they are much better than stock for friction. I think I will drop the cable back 1 click and try it and another one if its still really harsh.

As for that rotational whine I doubt that's going away no matter what I do. That was 100% not there before, even when the box blew and was missing gears.

 

The Noise could be many things...

However, this situation would warrant a disassembly of the Transmission for further inspection.
A Roller-Clutch, or an incorrectly positioned Valve-Body Bolt might be the source of the noise...
Only one way to find out.


I also do not like the behavior that you described as taking too long to Up-Shift...
This would not fly out of my Shop.

 

Sounds like maybe they put a different governor in your trans causing your shift points to be out of whack. Ask what exactly was done to it. Shift kit? As for the whine it could be a number of things. Break it in first and do a filter and drain and fill and see how it behaves. The harsh shifts will eat away at hard parts over time.

 

No he only replaced the clutch packs. Seals, rebuilt torque convertor and he had to fix the issue with the TV cable. A previous place ( before I bought the car ) forced a TV cable in there. It was really slack and started leaking where it goes into the trans.

the new TV cable I bought wouldn't fit. The plastic part that goes inside the trans was actually a few mm wider than the one in it and wider than 2 old GM cables I sent him down to compare. He also noticed the bracket on the carb was all out of whack so he redone the bracket so it's nice and firm now. I'm hoping it's literally just the cable that needs slackened off slightly.

 

Well the "Late and Firm" Shifts are indicative of excess TV Pressure...
Hopefully it is just the TV Cable Adjustment.

However... there still is the noise.

 

Yep, , , of the millions of these transmissions that GM put into their cars, there ain't a one of them that's "supposed to" whine like a Karen calling for the manager.....

Bottom line here =

You paid for it to be fixed, and it ain't....

 

Yup. I still havnt touched it as im ill at the minute. I will hopefully adjust it at the weekend and if it's still not right and makes the noise then it's going back I guess

 

Isn't it the case that there's only one setting for the TV cable and that would be the result from setting it properly in the 1st place?
And the geometry at the carb is also very important.
Which is to say, the TV cable isn't a "tuning" tool.
I had this conversation with Dana when we were discussing my somewhat bastardized 700R4. I had to back off on the cable so it wouldn't hang on so long and he said that is NOT the way to go. I face a burnt up transmission going that route. Further discussion and we came to an agreement that the reason I hadn't suffered a meltdown was due to .500" boost valve which was probably contributing to the line pressure.
It's always left me wondering.
FWIW, my now latest 700R4 is a shifting dream machine. Built by a true professional (not unlike Dana I would think) and every nuance of that transmission functions perfectly. Let's hope it holds up at the track.
Good luck to the OP.
Keep us posted.

 

For the record.

 

He did have to correct the bracket on the carb as he said it was at the wrong angle and full of slack. He showed me that when I collected it and it's nice and solid.

could the slight whine be the pump because the line pressure is too high? If slackening the cable a touch doesn't make any difference it will have to go back anyway. Its got a years warranty on it. Its just a pain because the place is nearly an hour away and the cars yearly test certificate runs out soon and I need to do the rear brakes and some other stuff first or it will fail ( I'm in the UK )

 

I'm wary of using the cable for any kind of adjustment to the shift points as I've been cautioned against it. But that doesn't mean it isn't acceptable on some level. Perhaps vorteciroc will chime in. His experience with these transmissions can't be measured.
As for the whine, this sort of thing is difficult to diagnose in a forum such as this. But I can ask a question or two and maybe that'll flush out an answer.
When does the whine occur. Idling in park? All gears? Does it change with engine RPM? Or in sync with vehicle speed?
With engine RPM in park or neutral and I would suspect the pump.
With vehicle speed and it would indicate something on the output side.
Only in certain gears would indicate something else again. What those might I couldn't say.
I was able to figure out some earlier transmission troubles using my ATSG service manual.
Indispensable I might add.
​​​​​​

 

As far as the Throttle Valve System goes... There is ONLY ONE ideal Position/ Setting.

With correct Bracketry/ Geometry... The Cable Adjustment CAN be set incorrectly too Lose or too Tight.

Effects are described by myself below:

 

That's always been my understanding so therein lies my trepidation towards messing with it if the shifts aren't right.
If the bracketry is messed up in some way, then the entire adjustment could be out of whack.

 

Yes if the Brackets are incorrect/ the Geometry is incorrect... then you have got potential issues.

With the correct Brackets and Geometry... To set the TV Cable:

-Disconnect the Cable from the Throttle Blade(s).
-Depress the adjustment/ ratchet detent, and push the TV Cable Piston/ Plunger all the way inward (towards the Fire-Wall).
-Reconnect the Cable to the Throttle Blade(s).
-Open the Throttle Blade(s) fully and release (the Piston/ Plunger will ratchet-out if correct).

If the Cable still looks/ feels loose it is too Long...
The Opposite and it is too Short.

 

Persactly (word of the day) as I have done for a couple of decades.
An issue I have come across are worn components. Often, I find the ratcheting mechanism doesn't quite work as it should. Mostly in the "hung up" aspect as in it looks like there could be another tooth or two to pull from cable but there's binding in the cable or deflection in the bracketry.
Finding the correct cable for the application is another issue altogether. From my research, I've come across at least 4 possibly 5 different cables lengths. Both the overall assembly length as well as just the jacketed part. TPI, carbed, TBI, truck, car, et al all serve to complicate what's really needed.