Can I ask a dumb transmission question here?

saudivette

Clueless In Sandland
Joined
Mar 24, 2008
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2,633
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Aussie expat in Saudi Arabia
Just to set the picture from the start, I know nothing about transmissions. Well, I know one thing - they are generally heavy and that you can't lie for too long on your back with a transmission on your chest!

When I bought my 82, I saw that it had 1 2 3 D on the shift "window". I said to the guy "oh, it's a 4 speed" and he said that it was only 3 as the previous owner had had a TH350 put in.

The car drove ok and it acted and drove like a 3 speed, although it didn't hold in first gear very well if you booted it.

Now, with all the work I've been doing on my Vette, I haven't even glanced at the tranny as I had no reason to mess with it however, I was forced to go under the car to retrieve a socket the other day (my Snap-on telescopic magnet was inside and it would have taken more time and effort to go and get the magnet than to *sigh* and slide under and get the socket) and I looked at the transmission pan.

It doesn't look like Texas, nor is it square with a corner cut off - it is basically square. To appease my curiosity, I had a quick look on the net and saw that TH700's have a square pan but the pics of square pans I saw look slightly different to mine :huh:

It'll be a while before the car's running and the transmission was way down on my list of things to attend to but when I saw Frank's post (Bird's "transmission whip" mate) I thought I may as well ask the question.

What is it? If 4 speed, why did I only get 3 of them? Why does it not hold in first for very long if I put it in drive and then floor it (ie, it doesn't "wind out" in 1st - changes to 2nd real soon)?

Just a passing curiosity at this stage, but chime in if you have an answer to my dullard questions :thumbs:
 
700r4 pan has 16 bolt holes,350 has 13. sounds like you do have the 700r4. make sure the tv cable is connected to the throttle lever at carb. If it is, make sure it is adjusted properly(when pedal is full throttle the tv cable should be at full pull,no slack). If that is ok,you have calibration problems or internal trans problems. The early units were real notorious for needing valve body and governor recalibration. We always install the transgo green box recal. kits in all our rebuilds.
 
Thanks Frank, I'll try and duck out tomorrow and count the bolts.

Is the 700 a decent box or should I bin it and get a 350? Fuel's .40c US per gallon out here, so fuel economy is not a priority :yahoo:. If I DO swap, what other issues are there, like tail shaft length etc...?
 
Thanks Frank, I'll try and duck out tomorrow and count the bolts.

Is the 700 a decent box or should I bin it and get a 350? Fuel's .40c US per gallon out here, so fuel economy is not a priority :yahoo:. If I DO swap, what other issues are there, like tail shaft length etc...?

You can debate this forever, but here is my 2Cents. If a 700-R is 89 or later, and built right, you can install 3.73 gears and have good acceleration, and still have good cruising RPM. Important here at $3.50 a gallon. You won't have the car there forever, unless you are planning on selling it when you leave.
If you really don't care, and just want a killer tran, the turbo 350 is a little stronger, and the T-400 is pretty much bullet proof.
The 700-R takes a 3" shorter D/S than the 350.
 
You can debate this forever, but here is my 2Cents. If a 700-R is 89 or later, and built right, you can install 3.73 gears and have good acceleration, and still have good cruising RPM. Important here at $3.50 a gallon. You won't have the car there forever, unless you are planning on selling it when you leave.
If you really don't care, and just want a killer tran, the turbo 350 is a little stronger, and the T-400 is pretty much bullet proof.
The 700-R takes a 3" shorter D/S than the 350.
I'll be taking the car home with me, but it'll become a "weekend warrior", not a daily driver.
I have no idea if this is the original box or not but if it is, and therefore PRE 89, does that mean it's not very good?
There's a million Caprice Classics and other Chevys out here, so I'm pretty sure it wouldn't be hard to get my hands on a good 350. However, the tail shaft would be a problem. I really wouldn't trust anyone out here to modify a tail shaft that wouldn't then vibrate like a bastard or shit itself one day when I was driving - go on, someone tell me that a tail shaft out of a ???? will bolt straight into an 82 Corvette with a TH350 :amazed: I guess it wouldn't be too expensive to get one shipped here surface freight.
Does the 350 have "better" street ratios than a 400? When I thought I had a 350, my intention was to put a shift kit in it and be done with it - something that changes nice and smart.
I've got to get the engine bay all back together, then drive it for a while then gut the interior - THEN we'll talk in earnest about transmissions...
 
'82? That is the first year of 700-R. It will have weak guts. You can get later doo dads, but Tim and Frank would know better.
 
Wayne,
Only the full size cars, Caprice etc and pickups use the long tailshaft. All the intermediate cars, malibu monte carlo etc use the short shaft, same as a vette. But they also used the smaller metric 200 trans so look close.
Mike
 
If you want to drive the car at highway speed (60-70mph) forget about the TH350. You'll need 2.73 or 3.08 gears to make driving at 70mph somewhat enjoyable.
I have 3.55 gears and with my TH350 it was reving close to 3000rpm at highway speed... even with a stock exhaust that's loud, now imagine that with Borla mufflers or Flowmasters :suicide:
 
If you want to drive the car at highway speed (60-70mph) forget about the TH350. You'll need 2.73 or 3.08 gears to make driving at 70mph somewhat enjoyable.
I have 3.55 gears and with my TH350 it was reving close to 3000rpm at highway speed... even with a stock exhaust that's loud, now imagine that with Borla mufflers or Flowmasters :suicide:

I agree, I'm running 3.08 rear gears with the stock 350 (it slipped A LOT) 70 was exactly 3000 RPM, since I changed to the 700, 100 is 3000 RPM and 70 is 2250.:yahoo:
 
Ok, from your comments, sounds like a 700 is the way to go. If the one in my Vette is the original 700, and therefore 82 vintage, I should probably swap it out with a later model one. I could probably get a bell housing made from solid gold out here for less than it would cost me to have a tranny shipped from the US, so what other cars came with the 700, post 89 as Bird said? In other words, what would be the latest model car that came with a 700 that I'd probably find out here?

What's a ball park figure for the transgo green box recal. kit that Frank mentioned and a set of gears to get the best of both worlds of bottom end accel and highway cruising? Or, am I being dull and the kit includes the gears?
 
I did a bit of reading. I assume I don't want a 4L60-E but a 700R4 or 4L60.

If that's correct, the list I've found says:
83-91 S15/Sonoma - TH700R4/4L60
85-90 Safari Van - TH700R4
91-93 Safari Van - 4L60
92 Suburban - 4L60
82-92 Truck (C/K series) - TH700-R4/4L60
83-90 Van - TH700R4/4L60
91-93 Yukon - 4L60

Obviously, I need to be looking for something post 89 but can anyone add any other vehicles to that list? I don't recall seeing any Safari Vans out here and I have no idea what a S15/Sonoma is?? There's 8 gazillion Caprice Classics out here (the big "jelly mould" type) what tranny did they have?
 
the vettes are calibrated different than other cars,the only other vehicle that comes close would be a camaro or firebird trans. or possibly an impala ss ('82-'93). the only problem I see using a later model is that the lock up in converter is different in the way the computer engages it. you would have to rewire the trans,or change vb and plate w/transgo kit and lu valve.I like the early units with the later input drum,sprags and pump,then I build the vb so it is all hydraulic,no electrical needed. the transgo box kit is just for the trans. valve body and governor,it is about $95.00.
 
Shit Frank, you completely lost me there :nuts: Also, what computer? Pretty sure all that shit is gone from mine. The Crossfire's long gone and I pulled out a lump of harness ages ago that wasn't connected to anything anymore...
 
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