It seems from what I've read on here that the biggest problem with combining a 3.4 with a worn out 700r4 is that the tranny tends to die shortly thereafter. Mine is shifting fine as far as I can tell, but it does have 187K on it. That and a few times over the last couple years I've gone up reeaally steep hills, it smelled.

I'm not looking to constantly chirp the tires going into 2nd and 3rd, but I would like to be able to haul a light quad trailer (hopefully I'll be able to get a truck for that) but just in case.

What are some things I can get for a v8 tranny and put in mine to beef it up a little. I don't really 'get on it' much, so the way it shifts now is fine.

I'm kinda debating if I should rebuild it myself too. Everybody wants about $1300 to rebuild or overhaul it. Is there anything in these 700r4's that are beyond the realm of the average 'do it yourself' mechanic.

I'll post this in the tranny forum too and see what comes up.

 

At a minimum with good results, I recommend that the servo be updated to the standard V8 unit, and a larger boost valve be installed. The V8 servo is the '553' unit. Should be able to find one used where that person upgraded to the 'Vette '093 servo.

For a boost valve get one in the .422 to .471 range. Can go to a .500 unit, but isn't required.

The servo installs from the exterior of the trans (pass side). And the boost valve installs from underneath. Need to drop the pan (good time for a filter) but not the valve body.

The SE site has a good servo install guide. Together they will increase the hold pressure while firming up the shifts.

RBob.

 

That is good info, but I would also change the spring under the throttle valve plunger in the transmission. It will get weak after a while and cause a low rate of line pressure rise. The 700r4 and 2004r both need a good boost in line pressure the second the throttle opens or they burn up, plain and simple.

I built two 700r4s in 30,000 miles behind performance engines, before realizing that I had almost no line pressure increase as the throttle opened. The TBI 355 that I had at the time made huge low-speed torque, just off idle. The result was failure of the friction material, due to slippage.

 

I asked a similar question at...

https://www.thirdgen.org/forums/v6/3...erent-3-a.html


looks like you posted there too

I forgot to ask, but the transmission will still shift smoothly right? Or will these parts make it **** super hard and extremely firm???

 

It will still have a decent shift. It is when the feed holes get drilled out and accumulators are stacked with washers that the shifts require neck braces for the occupants.

RBob.

 

Add in enough vehicle mass though and it results in fractured U-Joints and a chiped ring gear (stock GM 3.08s). That is one of the reasons I have the 4L60E now.

 

Anything you can do to a V8 case Th700R4 you can do to a 60 V6 case... Redraif's was built essentially to V8 specs, with extra clutches, a Trans Go shift kit, the Corvete servo, and a higher stall convertor (which is different, the V8 style is too large). It shifts firmly, but not so hard as to be a pain to drive.

 

Out of curiosity, but if i build up the 700R4 just back to factory specs and add a really good tranny oil cooler, will that be enough to make it last and still shift good behind a 3.4?

 

The parts aren't that expensive, the labor/knowledge of the trans guy is what you are paying for. I'd at least spring for stock V8 stuff.

 

ok, thanks LT1. The tranny people I go to are really well experienced in stuff. I'll run all this past them when I get it done .......depends when money comes thugh lol

 

I used the guts from a almost new 4L65E in mine.

 

i am having Ujoint trouble now due to that. Its fun hittin the gears but........breaking stuff sucks

 

I'd suggest going to a tranny guy if you don't have any experience.

I've rebuilt a 4L60E and I've almost finished rebuilding a 700R4 and they're rather complicated if you don't have prior experience.

Plus you need some special tools (piston compressor, special snap ring pliers, bushing drivers, etc.) that you won't have in a normal tool set.

 

Yeah, I may end up just taking it to a shop and tell them to put in the V8 servo and the bigger boost valves. I should also go with the extra clutches.

I might end up puting a trailer hitch on this car to haul my quad.

Of course though, I was thinking of getting another car to drive while the firebird is down. In which case I could just get a truck, or just save my money for now and drive the barely driveable 66nova.

 

Try to hunt down the Haynes GM Transmission Overhaul book (full rebuild sections with details/pictures of the 200-4R, 350, and 700R4) and the ATSG Transmission Rebuild manual for the 700r4, too.

The ATSG manual is a "reprint" of the transmission section of your GM Service Manual, but it will have any service bulletins in it too. Example, the '86 trans had some accumulator porosity issues; it's not mentioned in my GM service book, but in the front of the ATSG manual they have the TSB sheet.

Visit ATSG Home and on the left click on "bookstore". I got my ATSG manual from Northern Auto Parts: Home - at that website, choose (at the bottom left) "Tranny transfer case clutch kits rearend", then in the middle choose "Transmission kits, tranny...", and then on that next page in the "bottom" middle look for the words "Transmission Repair Manuals".

A few guys have made their own tools on here (such as the clutch pack compressor to remove the snap rings), could probably do a search in the tranny forum for "trans tools" or "transmission tools"...

An afterthought: I'm not sure about how much space you have, but as far as what to drive while the Firebird's down... what about getting a junkyard 700r4 from a v6? Then you could rebuild that and still drive the Firebird. Remember too that you should flush out your trans cooler before you install your new rebuild; Northern Auto (and I think Summit Racing) sells the spray can flusher- you don't want any metal filings from your old trans to get into your new one!

 

The way I had mine set up was if I was at part throttle it will shift nice an smooth.
I go WOT or close to it, it will chirp, lurch and squeel.

But you have to change acumulator and adjust the TV for it.