Transmissions and DrivetrainNeed help with your trans? Problems with your axle?
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
Ok this forum seems to cover the 700R4 to TH350 swap religiously yet I've seen but 1 thread through 3 pages of searching that dealt with someone swapping a T5 out in favor of the TH350
I need to make sure I have all the bases covered before continuing on. Yes, I do realize that I will learn from mistakes and such but if I can avoid them then I will try my damndest too. I'm messing with my daily driver here and downtime is somewhat of an issue.
Just to cover base, here is what I gathered from the 700R4 to TH350 swap.
2. I go to a junkyard and find myself a 700R4 tailshaft. Will it matter what 700R4 it came from?
3. Have my driveshaft lengthened 3 inches. I do not know the difference in length between a T5 driveshaft and a 700R4 driveshaft. What I gathered from the 700R4-th350 swap threads, if its a 6 inch tailshaft TH350, the driveshaft needs lengthening by 3 inches in order to be long enough to fit into the transmission.
4. Speedometer. I read that using the 700R4 tailshaft will allow the person to go without doing any modifications. But since this car is a T5 car, what, if any, modifications are needed to make sure the speedo is working correctly.
Thanks for any replies and advice I receive, I definitely will appreciate it.
there are 3 diffrent sizes of tailshaft on a TH350(I forgot the accual sizes), one gives the same length as our TH700r4, in which case you will not need any adapters or special legnth driveshaft, also the speedo hookup is the same as long as it's a mechanical speedo on the old and new transmission, you will need someware to bolt the tourque arm to, and a crossmember that has the tranny mount point in the proper location, this crossmember http://www.spohn.net/product.cfm?productid=1303 from Spohn fixes both problems, also remember to hook up the vaccume kickdown on the th350, also if the TH350 dosen't have the right legnth tail shaft, you will either need a new driveshaft to compansate or that adapeter (it seems too complicated....I'd just go with the diffrent legnth D/S)
__________________ 84 Z-28 in the prosess of re-build:
383, steel crank, forged pistons 4 bolt block .040 over
comp cams nitrous XP 288HR
Adv dur 288/315
Dur@.050 236/248
LSA 113
valve lift .520/.540
"quiet" gear drive
polished and ported trick flow 23* heads
comp P/N 26918-16 beehive valve springs
steel full roller rockers
edelbrock pro-flow 1000 CFM EFI port mached to heads
Venom 36 lb injectors
edelbrock nitrous sys, 150 shot
hooker 2210 1 3/4 pri headers
powermaster starter
powermaster alternator, 160 amp
'97 T-56 transmission
centerforce dual friction clutch
pro 5.0 shifter
richmond 3.73 gears
eaton posi
spohn K-member
spohn "wonderbar"
spohn torque arm/crossmember
spohn lower control arms
spohn A-arms
spohn panhard bar
spohn subframe connectors
dual exauast, 3" up to cut outs
nordskog digital dashbord
trippel gauge pilar mount
digital fuel press.
digital nitrous pressure gauge
digital oil temp gauge
Thanks, you know how much something like lengthening a driveshaft would cost?
Also, the speedo hookup, anyone have anything to add about that? If the T5 I have is mechanical and the TH350 is mechanical, shouldnt i be able to hook up the speedo to the TH350 without any problems?
the only thing you have to worrie about is getting the right speedo gears from gm for your rearend, find the ratio out and tell them you need the a speedo gearset for a th350 with you rear gears and they should be able to hook you up...as for the driveshaft....I have no idea...I'd say around 150-200, but it would be a guess.
__________________ 84 Z-28 in the prosess of re-build:
383, steel crank, forged pistons 4 bolt block .040 over
comp cams nitrous XP 288HR
Adv dur 288/315
Dur@.050 236/248
LSA 113
valve lift .520/.540
"quiet" gear drive
polished and ported trick flow 23* heads
comp P/N 26918-16 beehive valve springs
steel full roller rockers
edelbrock pro-flow 1000 CFM EFI port mached to heads
Venom 36 lb injectors
edelbrock nitrous sys, 150 shot
hooker 2210 1 3/4 pri headers
powermaster starter
powermaster alternator, 160 amp
'97 T-56 transmission
centerforce dual friction clutch
pro 5.0 shifter
richmond 3.73 gears
eaton posi
spohn K-member
spohn "wonderbar"
spohn torque arm/crossmember
spohn lower control arms
spohn A-arms
spohn panhard bar
spohn subframe connectors
dual exauast, 3" up to cut outs
nordskog digital dashbord
trippel gauge pilar mount
digital fuel press.
digital nitrous pressure gauge
digital oil temp gauge
You cant just bolt a different length tailhousing onto the TH400. Well you can, but it won't work. You need to change the tailshaft also. That requires tearing the whole tranny apart and swapping tail shafts. Not very hard to do on a TH350 (couple of hours of work), but I am not sure it is something you will be able to tackle. Just get a driveshaft from a Camaro that orginally had a TH200. All 1982 automatic equipped Camaros have them. I have one, but I am not sure I want to part with it. What is it worth to you?
sorry to revive a dead threat but i am doin the same swap and am a bit confused as well. so i will have to change the crossmember for the trans mount location? and what of the kit B&M 30299? is this useless to me here? and the five speed drive shaft is too long/short it too must be replaced?
It's not that bad of a swap. Basically you will need a torque arm kit from b&m to bolt the factory torque arm to the th350 tailhousing. It's $99 from summit. Then you will need a crossmember, you can either get a custom one from sphon or umi for ~$100 or get a used stock 700r4 crossmember and use the supplied bracket from the b&m kit above. In fact, I have an extra one you can have for free. Then you will need a shifter, I would deffinately go with a b&m console megashifter because it looks nice and comes with everything you need plus instructions, brackets, and a cable. It's ~$200. You will have to use a couple of home fabricated brackets to support the front of the shifter since there is a big hole where the 5 speed shifter used to go, it's not that bad though, I have some extra steel brackets you can have too with holes already in them. You will want to run a transmission oil cooler. I use the supercooler from b&m, it cost me ~$70 from summit. You will have to run your own tranny cooler lines. Some brake line coming from the tranny with rubber line going to the cooler will be fine. Depending on whicn th350 you get you may need to have the driveshaft lengthened. The "long" (medium) tailshaft th350 is the most common and is a direct fit, however if you have a short talhousing th350, you will need it lengthened. It cost me about $170. Keep in mind that your speedometer gears will most likely be off also so if you want your speedo to work right you will want to swap them before the tranny goes in.