I'm new to this auto tranny stuff and could use some help. I've got a buddy willing to rebuild a 700r4 for my next project and wanted some opinions and information. I "think" I want a reverse manual valve body (tell me if I'm wrong here) and would like some info on how this works, what it will cost for parts, and any other tricks to beef up this tranny. Plans are for a 383 stroker motor running on propane, 700r4/np205 combo, and rockwells. Thoughts?

If I were to do it again I'd definately go a manual valve body type setup. or see if there is any way to keep it from shifting if your in a lower gear. Crawlin in stupid low sucks if it shifts up. It'd be nice to have it shift like normal in drive but stay in a set gear if your lower than drive.. Dunno if that's possible but I'm sure someone here will be able to tell.. Plenty of beef parts are available nowdays.

Replace the OEM reaction sun shell with a HD aftermarket unit. That is what took a dump in my 700R.

first off, thanks for your confidence in me. i'll try to prove myself.

first question that comes to mind is "why a th700?!" i know they have a 3:1 first gear, but why not run a th350? yeah, i know, they only have a 2.5:1 first, but who cares?! the converter does most of the work for you anyhow and between it's torque multiplication and the super low gearing in the rockwells, i don't think you'd notice a difference.
other reasons why i'd go with the th350:
1) shorter, more driveline clearance for front drive shaft
2) less weight
3) waaaaay cheaper to build
.................
also, if you use the lokar shifter, you can put a 700 in first and keep it there. reverse manual valve body kits are not cheap or easy to install, unless you're a tranny builder. and then you have to shift up and down every time. needless to say, i'm not a big fan.
other issues with the 700 are case and parts strength or lack thereof. the cases don't do well with a cast iron transfer case hanging off the back unless properly supported, or they will crack. other than that, i'd go with the aftermarket sun gear shell (as previously mentioned) and a better 3-4 clutch setup (couple of options). and definetly with a HD converter. also, make sure you run a good trans cooler no matter what. heat is an autos worst enemy.
i know this post sounds likt i'm harping on 700s. don't get me wrong, i'm a big fan of 700s in the proper application. both my wife's fj60 and my fj45 are receiving 700 transplants, but they get driven to the trail and everywhere else, which warrants the OD and extra expense. for a dedicated trail rig, i'd run a 350 any day. :)

You definitally want the manual valve body. I have a 700R4/np203/tlc 3sp setup and when I'm in 1st/lo/lo 140:1 is too low. Yea, I can play with the cases, but it would nice just to start out in 2nd or 3rd.

Also it would be nice for the tranny to shift when I want it to.

HTH,

Good questions all. As you gathered, my main reasons for the 700 are the low first gear, the overdrive , and the fact that I picked it up already set up with the np205. The rockwells came along later in the parts gathering phase. I want this rig to be able to make short runs on the street( don't freak out about this - I'm only talking 15-20 miles at most from one trail head to another). I know that the th700 got a bad start and the early models were crap but I believe one can be built to stand up reasonably well with the aftermarket parts available today. All that said - you're probably right about just using a th350. I had not thought about the driveshaft clearance issue. I have no idea how that will work out with the top loaders. Damn - just when you think you have a plan! I guess I could take a page from J. Proffit and run a two piece front shaft with a carrier bearing(?). I think I would enjoy the manual valve body as all my other rigs have been standards and just elimenating the clutch would be a great help. I didn't know about the Lokar shifter thing - that's something to consider. Ballpark - how much are we talking about for the parts to make the other modifications suggested? Thanks again for all the valuable help and knowledge!

if you alraedy have everything, run it. luckily the 205 front output is a ways down and to the pass. side, so your driveline should be ok. on some other conversions they're a pain in the neck cause the front output ends up very close to the trans pan. in your case you might want to opt for the 2 piece front, otherwise the front driveline might smack the trans pan under full suspension compression.(make sure you have plenty of clearance under the engine oil pan also, my old chevy with rockwells smacked the oilpan with the pumpkin).
short runs on the street should be ok. my truck had 44s with the th350 and a big block and it did ok, but only up to about 50mph. not recommended for the faint of heart. and make sure your brakes are up to par. mine were scarry at high speed. i do have a set of outboard front disc brakes for sale for the rockwells if you're interested.
back to the 700. the preffered years are late 87 thru 92, also called the "auxillary valve body 700". those years have all the factory upgrades. after that, they went to computer controll, hence the 4L60E. between the HD shell and a severe duty 3-4 kit you can expect to pay about $100 including shipping, but the trans has to be disassembled to install these parts wich will take some time (labor) and entails using at least a gasket kit, possibly an overhaul kit at the same time. if you need any of that stuff, let me know. i sell trans parts for a living.
the reverse manual valve body you'll have to get from TCI or summit or jegs. not something i have access to.

Thanks orangefj45 - you're making me feel a little better about my plan. I knew form reading some of your earlier posts that you worked in the industry. You seem to have a strong handle on this stuff - that's why I wanted your opinion. If I may, I'd like to ping you off line to work on getting some of the rebuild stuff. The guy that has my 700 now is an "old school" tranny guy so I thought I might be able to ease his load by sourcing the parts needed. Thanks again for sharing your experience.

no prob. here to share info. i know how much i've learned on this board and it's been a great resource for me.
pm me.

Well - looked at the prices for the reverse manual valve body and it aint gona pass the "bang for the buck" test. I think I need to learn more about this Lokar shifter thing about it's ability to hold it in first. Any detail? Thanks - D

look on lokar's website or find a good speed shop, they normally stock that stuff.

no prob. here to share info. i know how much i've learned on this board and it's been a great resource for me.
pm me.

Thanks a bunch for the info!

I've just picked up a 4.3 Vortec for the 45 and was trying to decide on a tranny... I have a brand new th350, but since this will be my daily driver I'm going to go 700r4. I have plenty of wheel base, and the overdrive will be nice.

Time to go shopping :)

GO with the 700, it is a killer tranny, the 1st gear is worth it, especially with a 205.

No need for the Manual valve body though, it will stay in 1st gear and at times, you want that "shift" from 1st to 2nd to help your momentum.....

My 4L60E has a Lokar and I can keep it in 1st for compression braking.

i've got a b&m unimatic shifter with my 700 and it will stay in 1st...

will anything other then manual valve body keep it in another gear other than first tho? I'm curious on that. SOmetimes starting in first is too slow with stupid low gearing and a higher gear would be nice. When they shift in stupid low they shift really hard and quick..

pretty much the only good reason to run a manual valve body is to have the ability to take off in any gear, not working your way up from 1st.
that way if you're in the sand or similar environment, you can take off in 2nd or 3rd. :)

will anything other then manual valve body keep it in another gear other than first tho? I'm curious on that. SOmetimes starting in first is too slow with stupid low gearing and a higher gear would be nice. When they shift in stupid low they shift really hard and quick..


nope. :(

I run a B&M shifter and my th700 stays in first. I was going to go with the Lokar, but was worried that the solid connection (vs the cable linkage of the B&M) may pop out of gear (or into another gear) under really bumpy situations or if the truck was torqued a lot. It doesn't sound like you guys running Lokar's have had that problem. I may revisit the Lokar shifters. Any input welcomed.

On topic: I really like my 700r4. I daily drive my forty and regularly drive from Salt Lake to Moab and the OD is invaluable! I've never found that I need a lower first gear...yet.

the lokar shifter looks great and works ok. they are kinda flimsy and sometimes it's difficult to shift up only one gear; the detent is not very good.

pretty much the only good reason to run a manual valve body is to have the ability to take off in any gear, not working your way up from 1st.
that way if you're in the sand or similar environment, you can take off in 2nd or 3rd. :)

I've got a rev. pattern manual valve body. It is very nice to have 1st gear right next to reverse.

[semi thread hijack]
So yesterday I go to drive my 60 (350, 700r4, split case) to work, but realize its not shifting into 4th. I can't make it shift into fourth, I checked the shifter linkage, the tv cable, etc., but it won't go, even if I get up to like 55 mph (usually shifts around 45). This is after a rebuild of the t-case, and the only thing that has changed with regard to the tranny is installation of a drain plug and switch to Mobil 1 Synthetic.

any ideas?

-Travis

[\semi thread hijack]

I agree with Charles on that one for sure...real easy to go between 1 and r....the valve body is a no brainer 1 hr install that can be done down the road if you like and the lokar is a nice shifter...detent needs work but otherwise ok...

"the valve body is a no brainer 1 hr install that can be done down the road "
now that's what i want to hear! if I did my basic research correctly it also does away with the TV cable when you go full manual? And all manuals are reverse? Kinda makes sense. ONly one I saw was summit about $250 or so..
I'll file this away for a winter project.

"the valve body is a no brainer 1 hr install that can be done down the road "
now that's what i want to hear! if I did my basic research correctly it also does away with the TV cable when you go full manual? And all manuals are reverse? Kinda makes sense. ONly one I saw was summit about $250 or so..
I'll file this away for a winter project.

All manuals vb's are not reverse pattern valve bodies. When my tranny guy built my TH400 with a rev. manual vb. he had do some internal changes. Probably because of the reverse pattern.

It was not a matter of swapping out the VB which is very easy.

any body gonna answer my thread hijack? :(

is it downshifting correctly when you punch it?

Found it on summit for $311. Anybody find it cheaper?

Make sure you get the TCI part number 376015. You want the engine brake for going down steep "things". :smokin:

www.jegs.com had them for $247 for TCI part number 376010. Don't know what the dif is though?

Another question, how can I tell what year this used th700 is. are there number codes on the case, identifying marks, ??

is it downshifting correctly when you punch it?
yes, it will go 3-2, 2-1, but never 4-3, b/c it never gets to 4. :(

Another question, how can I tell what year this used th700 is. are there number codes on the case, identifying marks, ??
that's possible, but difficult. there is a plate on the passenger side but decifering the info is tough.
best way to tell is by counting the splines on the input shaft; 27 or 30, the later being the one you want. also, you'd want the "auxillary valve body style" th700. only easy way to well is to pull the pan and look for a small steel tube ( about 3/16th inch diameter) that goes from the pump (front) to the auxillary (aluminum) valve body (rear) of the trans right over the top of the cast iron main valve body.