Question: My 84 Firebird has an original 700-R4 auto tranny that is starting to give me problems and I'm interested in replacing it. I've noticed a lot of people saying to replace it with a 700-R4 from an 88-up car. A few questions on that:

1. Will the newer 700-R4 just bolt right into place on my 84 with no modifications?
2. The big junkyard around here already has transmissions pulled so it's easy to purchase. Is there anyway to differentiate an old 700-R4 with an 88-up one just by looking at the transmission itself?
3. Do the newer 700-R4's shift smoother than the old ones? My 84 gives a distinct "clunk" when it shifts into gears, even after a fluid and filter change.
4. Do I need to get any other parts besides the tranny itself (cables, wires, etc)?
5. What would be a reasonable price for an 88-up 700-R4 at a junkyard (so I can make a reasonable offer)
6. Finally, what exactly ARE the years that the "improved 700-R4" were manufactured?

Thanks,
J

 

That clunk may be the universal joint on the driveshaft. , but that's not a hard fix.

 

Anybody know the answers to the questions? I plan on going to the junkyard early next week.

Thanks,
Joe

 

1. Yea depending on the tailshaft thats on it. but that is easily swapped.

2. I believe the 88up have a rainbow like disign in the casting by the tranny cooler line ports.

3. The 88up have a secondary accumulator which smoothes out that big clunk when shifting from P/N into gear.

4. You should swap your origninal TV cable to the new trans.

5. Personally i wouldnt screw around with a JY trans unless it was real cheap...

6. 88up...

 

that pretty well sums it up.
casting line like a rainbow near cooler lines on case. Secondary valve-body assembly with extra accumulator. Commonly had more clutches. Also better pump(older usually had 7-vane, later had 10)
- the year split is 86-1/2, not 88.

 

Is there an issue with the spline in swapping my 84 700r4 for a newer one? I don't know if it's 27 or 30...

J

 

I believe the convertor splines are different. The '82-'84 is the smaller spline count, with the '85s and up having the larger spline count/size.

RBob.

 

So basically, I should grab the torque converter as well as the tranny, correct?

Thanks,
J

 

Yes, just to be sure. you dont want to have everything apart and find out you need a different TC!

 

Yes, the older models had a 27 spline input, then later were 30. The tc is different and will not work.
- I would highly reccomend getting just the trans, having it freshened and getting a new TC.

Used driveline - you end-up spending time and money on someone else's junk...

 

What would be a decent price to pay for a junkyard 700r4 tranny? I'm going out there tomorrow morning.

J