27 spline 4l60 1

[chevy383ss]

im about to work on a 4l60, but i dont know if its a 4l60 or 700r4. the output shaft is a 27 spline. i havent counted the converter splines. anyone know if this is a 700 or 4l60? ive heard one of the biggest differences is the # of splines. as far as i know its out of an 89, but the valve body looks like an early 80s one. its a custom application for a limo, and its got to hold up to the weight. if it is a 700, should i tell him to junk it and get a 4l60?

 

[aliusSS]

I don't know how to tell the difference by looking at output shafts but from my understanding and from what i have been told and seen, the difference between the 4L60E and 700R4 is pretty much electronic(4L60E) to mechanical(700R4) sensors and wiring for speedo and what not. Thats the only way I know how to tell the difference between the two. The 700R4 and 4L60 have the same gear ratios and supposedly same internals also but main difference being electrical to mechanical. When looking at the aftermarket for parts for the two, they use the same parts(converter, rebuild kits shifters etc...)so i believe they are the same. So in saying that, no matter what it is make the decision to keep it based on if you have the electrical wiring to run the trans or not. If I am wrong let me know. Hope this helps.

 

[patdaly]

The 4L60 was created when GM changed their transmission nomenclature. Functionally, it is the same as the 700R4. The 4L60E is totally electronically controlled.

Built right, it could take Limo service for a reasonable length of time.

 

[chevy383ss]

pat, any suggestions on what mods i should do? would a regular stock rebuild hold up to the weight? should i recommend the blue plate clutches, or even the raybestos z-pak? what about the boost valve? i know itll give greater holding capacity, but the downside is a slightly firmer shift. the most important thing about the tranny is that it has to shift comfortably. but i would like it to last as long as possible, but those are at 2 different ends of the spectrum. its going behind an 88 camaro TPI, as far as i know the engine will be stock in the end.

 

[trailingwire]

later units have more brgs instead of washers, larger input shafts, early valve bodies had mechanical and electical control of lock up. some elec was from computer and some used a special vac switch which opened under high vac or low vac. you need to get help on this unit in several important areas. it is a good trans when built properly just puting a kit in it isnt rebuilding it . also converters vary by stall and the type of lock up. some lock up is direct and some have modulated onrs

 

[trailingwire]

later units have more brgs instead of washers, larger input shafts, early valve bodies had mechanical and electical control of lock up. some elec was from computer and some used a special vac switch which opened under high vac or low vac. you need to get help on this unit in several important areas. it is a good trans when built properly just puting a kit in it isnt rebuilding it . also converters vary by stall and the type of lock up. some lock up is direct and some have modulated ones

 

[trailingwire]

87and later have a better input sprague and a aux valve body which was a input clutch accumalator early ones had a pin that came loose

 

[patdaly]

Chevy, Im not a tranny guy, but I have seen what people like Hipster up in Wisconsin have done. He ran a 700R4 behind a 540 CI BBC in his box van, and it held up. Check out the reputable places like Art Carr or Hipster for proven suggestions.

 

[pishta68]

trailingwire, I just dropped the pan on my 98 Suburban 5.7 4L60-E trans and found a few tiny torrington bearings in the fluid and a bunch of silver mud on the magnet. I thought the filter was clogged and wasnt letting the trans hold a gear. It was slipping and lurtching and making a high pitched squeal, like a belt was loose. I changed the filter and fluid and now she drives fine. Is this thing going to explode or can I put another 134K on it? Does the TC have a torrington bearing in it? Thanks

 

[modistran]

700R-4 in the limo. What ever you decide make sure you have control of lock-up and the throttle pressure is exact. All heat in the trans is generated in the converter and driving at highway speed in overdrive without the converter locked up will super heat and fry the unit in short order.Any good rebuilt unit will give you many trouble free miles.You won't need racing frictions,put a corvette servo,plug the bleed hole in the drun with a bb,use good atf and hang a cooler on it.We put over 100,000 miles on a 92 streached towncar with a AodE in it.