Got to drive my car down the drive way and the transmission pump went out, lol, and now i dont know if i should just replace the pump or have the tranny gone back threw and beefed up some more, or should i throw the damn 700r4 out and get a turbo 400 to replace it? What all do i need to do so.

 

Man this is just my $.02 but i wouldn't keep the 700r4 unless I had a probuilt or something equivalent, just toooo many problems with them (yeah I know some of you guys out there have been very lucky). If you gotta have overdrive I'd go with a 2004r or 4l60 swap, otherwise a th350 would be nice. Again to each his own, I just don't care for the d%^* things.

 

Probuilt and never worry about it again. It's the right way to build a 700R4. Unless you're making over 600HP you will not have to worry. Neither a TH350 or a 4L60E/4L65E is any stronger than a 700R4. A TH400 is stronger, but why waste 25% of your engine's power before it even hits the rear axel? It also lacks overdrive. If you need serious beef and overdrive then you want a 4L80E, and I hope your check book is water cooled.

 

LOL well my check book isnt water cooled, but i bought a TCI TH400, TCI 3500 stall, Spohn cross member, Spohn driveshaft, so this should old up for awhile, the 700r4s are good if you want the overdrive for driving, but just one more gear to shift and slower times, i have 4:10 gears and 400+ hp, i dont need overdrive, and 4L60Es are a weak tranny as well, 4L80Es are a good tranny but not cheap, Im a ford tech, but drive GM..lol so i work on them all the time.

 

The 4L60E is basically a 700R4 that has the shifting controlled electronically. There are a few internal upgrades as well. GM just switched over when they went to the fully electronically controlled transmissions. Then with the LS1 they made some more upgrades and the 4L65E was born. In stock form the 700R4/4L60E is probably not up to 400HP, but properly built they can take 600 or more.

At this power level it's doubtful that a 700R4 would post worse times than a TH350. The 1-2 spread isn't as big a deal as most people make it out to be. At this level a TH400 is probably costing you some time in the quarter. Ultimately it's your car, but I am just not a fan of the TH400 until power levels get up above 600HP and the added beef justifies both the extra weight and the inherent inefficiency of the trans.

For years I drove a Chevrolet and worked on a Ford. Lately I've been driving a Ford and working on Chevrolets...

 

Yeah, but i thought i better get a good tranny now, instead of taking trannys in and out, because this next winter the motor will get redone, with a set of aluminum heads, and bigger cam, and a full forged bottom end, and Im looking at getting 500+hp then and want in the 11s for a street car, with the new ford 9" rear end, so ill get the tranny out of the way!! Thanks

 

depending on what you want to spend, you can find a good used tranny and be back on the road real soon for cheap. maybe install a B & M kit. it will help w the longevity of the tranny

 

Seriously, the consesus is that B&M shift kits are junk. There's about a hundred posts that bear that out. I've used them personally in two different vehicles and found that you get an ultra stiff full throttle shift, but it comes with the expense of harsh part throttle shifts. B&M has you blocking the accumulators solid, so there is no accumulation for the shifts, which in part causes the overly harsh part throttle shifts and can lead to the breakage of other parts. The B&M setup is a wham bam thank you mam deal. It's overly simplistic, with the only real goal being to get a hard full throttle shift.

I made the switch to ProBuilt's TransGo kit with the first 700R4 I rebuilt and the difference is night and day. The ProBuilt TransGo kit hits the gears just as hard at full throttle, but the part throttle shifts are nice and smooth (I actually think they are smoother than stock). The kit is much more involved and a bit more expensive, but you get exactly what you pay for.

 

Have the 700R4 built. It's a great transmission with the right parts and the right builder.

 

I guess I didn't mean B&M specifically, I meant to say a shift kit to help improve tranny fluid flow. That's what My tranny guy told me. Never mind the B&M stuff.

 

The real reason a shift kit can improve transmission longevity is that it reduces the slip time of the clutches. That's what eventually causes a trans to need an overhaul. The clutch plates, just like the clutch plate on a manual trans car, wear out over time and need to be replaced. When an auto shifts it uses the clutches (and sometimes the band) to allow one section of the trans to spin, while another section is held firm. During the shift one set of clutches slips out of engagement as the other set slips into engagement. The shift kit reduces the time spent in slip, which directly translates into longer clutch life, and therefore transmission life.

 

That maybe what I was told, it was a while back. What you are saying makes sense.

 

I had s 700 rebuilt in my 87 chevy a while back, and it costed me just shy of 2k. I'll never go there again. I would have found a good used one, and took my chances if I could do it all over again.

 

If you're looking to hold stock power, a used transmission would be fine. When I dropped my engine in, I didn't want to ever have to worry about the transmission, so I had my transmission guy put everything he had into my 700R4. Transgo shift kit, high volume front pump, billet input shaft, TCI lockup kit, 2300 stall converter, corvette servos, kevlar bands and "Z Pack" kevlar clutches. Some other goodies too. It's good for 600 HP and it shifts amazing.

 

I could probably use a high volume pump in mine. That's what happened to my Silverado. I was pulling someone out of the ditch, and my pump gave out and circulated pieces of metal throughout my tranny. Does a high vol pump increase line pressure, or withstand more line pressure??

 

Not necessarily. Volume and pressure are not the same thing. You can have more voume at stock pressure, and stock volume at higher pressure. A high volume pump will flow more fluid volume, but you need a pump that has a stiffer bypass spring to get more pressure. A lot of shift kits will have you change this spring (you are actually changing a part inside the pump without taking it out of the trans, as it can be done from the pan area).

Early 700R4s had, I believe, a 7 vane pump. This was eventually upgraded by GM to 10 vanes. I have seen aftermarket units with 13 vanes. I run the 10 vane in mine, with pump guts that came in my Pro-Built kit.

 

How many vanes does an 86 700 have?

 

Not 100% sure, but my '87 had 10 from the factory, so I would say there's a 99% chance that an '86 has 10 too. I think it was only the early ones that only had 7, like '82-'84.

 

Did the 86 700's have any other upgrades besides this since the earlier ones?

 

Round about '86 they added the auxillary valvebody to the 700R4. I'm not sure of the exact reason for this. Earlier trannies just had a plate in that area I believe. The 3/4 clutch pack got progressively better as the model years passed. I'm sure the pack in the '86 trans was better than the early units. That's about all I know. The '86 should be a good candidate for a performance build.

 

I believe my tranny had a shift kit done to it by the previous owner. I would have to take it apart and look. I'm just not a tranny guy. To me they look like a swiss watch. But anyway, maybe some improvements were made w/o my knowledge.

 

Even if you took it apart you probably couldn't tell if it had a shift kit. The springs are inside the valvebody and the only other difference is some holes drilled out in the seperator plate. You'd need a diagram of the shift kit and the appropriate size drills to verify it.

 

The only way I can tell is the way it shifts. I was told by others who know more about this stuff that I have a shift kit. Important thing is, is that it works well!

 

If it shifts well and you like it then I say drive it!

 

Amen to that!