Viper T56

[AU Doc]

I have a T56 out of a Viper that I bought off eBay for ~$500 probably 10 years ago. I'm planning for an LS swap, and I'm wondering if I'd be better off finding an LS3+T56 out of a junkyard or find an LS3 and figuring out how to adapt the T56 I have to work with it.

Any idea if this Viper T56 is worth the trouble?

[CliffsBlueCamaro]

I've got a Viper T56 behind my SBC. It works well with my engine, but there are some definite "quirks" if you want to use it with the LS.

Given that you've all ready got it, I would just keep it. LS T56's are only getting more junky and expensive, and that's when you can actually find one. You could sell it and go with a new T56 Magnum, but you easily be $2K out of pocket on the deal.

If you want the most simple route, look into this bell housing --> https://www.summitracing.com/parts/qti-rm-6038

You'll also need a custom bronze pilot bushing that has the OD of the LS crank, and an ID of 0.75" for the Viper input.

You could also swap out the front plate and input shaft for regular LS1 parts, and use a regular LS1 bell housing and pilot bushing. A member named "overzealous" on here did it that way. This might actually be the most economical route.

You'll also need an adjustable cross-member. I used the one from BMR and was very pleased.

For the shifter, look into a shifter from a 2004 Cobra. It bolts right up to the Viper trans, and doesn't have the weird right-angle that the viper shifter has. It comes straight up out of the trans in a nice position.

Also, don't forget that the Viper uses a huge 1350 slip yoke. Just something to think about when you are getting ready for a drive shaft.

Let me know if you have any other specific questions. I've done a ton of research on the odd-ball Viper trans. I'd be happy to pass on what I know. :-)

[AU Doc]

Sweet! Excellent info!

I'm thinking swapping the front plate and input shaft may be the way for me to go. That way if I ever manage to let the inside parts out of this thing, it will make swapping in a replacement a matter of finding another LS T56 (or I'm guessing a T56 Magnum).

What's the recommendations for the clutch assembly and actuation? Are hydraulic throwout bearings the way to go? Is there a good conversion kit, or will I need to source parts separately?

[CliffsBlueCamaro]

Any good LS replacement clutch will work. I'd look into a stock LS7 clutch. They seem to be good clutches that aren't that expensive.

You'll have to go hydraulic - neither the stock LS bell or the quick time bell have a pivot ball/clutch fork. There is a complete hydraulic conversion kit from McLeod that is around $600 if you want easy bolt-in. You could also use stock LS stuff if you swap the mid-plate. There is an inexpensive bracket you can find that mounts the master cylinder to the firewall (but most need some "tweaking" to get the right angle).

If you really want to say with manual linkage, there are a few options I would look into. I'm fairly certain that there is a bell housing that will mount an LS T56 to an LS engine which uses manual linkage. I don't remember the manufacturer, but I would check Quick Time. So that would mean swapping the mid-plate and input AND getting a pricey bell housing. It would likely be cheaper to just go with stock hydraulics in that case.

Here's another off-the-wall idea for you: You could also use a stock BBC 621 bell housing with the McLeod T56 adapter plate. In theory this would place the transmission in the same location as a "stock" 4-speed, and plenty of people have successfully mated these to LS engines (with the use of a thicker flywheel and a bolt-on z-bar pivot too). This is an idea I've kicked around since I already have the trans working in my car. I could basically treat it like I'm still using an original 4-speed since it works with my current SBC, and just swap in an LS. An added benefit besides keeping manual linkage would be that you can use 11" BBC clutches that are really inexpensive.

[AU Doc]

I'd much prefer a hydraulic setup. I've never been too fond of the feel of mechanical Linkages.

let me make sure I've got this. I can swap the front plate and input shaft for an LS version, use the bell housing you linked above, the McLeod hydraulic throw out bearing and MC, and I can use my viper trans. Then, if I ever break the thing, I'll be able to swap in a T56 from an LS or a T56 Magnum? Will the overall length be the same?

[CliffsBlueCamaro]

I'd much prefer a hydraulic setup. I've never been too fond of the feel of mechanical Linkages.

let me make sure I've got this. I can swap the front plate and input shaft for an LS version, use the bell housing you linked above, the McLeod hydraulic throw out bearing and MC, and I can use my viper trans. Then, if I ever break the thing, I'll be able to swap in a T56 from an LS or a T56 Magnum? Will the overall length be the same?

If you swap the input and front plate then you would use a stock or stock replacement LS bell housing.

The Quick Time one in the link will mount it up to an LS if you keep the Viper input and midplate.

I have a diagram that says the over all length of a Magnum is 33.8" (from input tip to the end of the output housing). I can tell you that the shifter location will likely be different - the Magnum diagram says it is 26.6" from input tip to the stub of the shifter. I think the Viper shifter is a smidge further forward than where the LS T56 shifter is. I don't know how big of a deal that is to you, but you might have to open the shifter hole up another inch or more to the rear with a Magnum. Compare those measurements to your trans, and let us know what you find. I would do it, but I don't feel like jacking the car up right now...lol

[AU Doc]

I appreciate all the help!!! I've been traveling this week and I'm limited to the tiny screen and keyboard on my phone. A lot not the web pages don't play nicely either.

The more I read about this viper trans the more I like the idea of using it. It's currently buried in the shop behind an untold number of other projects. I need to go drag it out and have a look. I also need to read up on the durability of the LS input shaft to see if swapping over or keeping the viper shaft is a better idea.

[CliffsBlueCamaro]

No problem - I've been reading on the Viper T56 for a long time now, and I'm just glad I can help someone else out. They can be a bit tough to find good/specific info on.

Lots of people say that the Viper input is stronger than the stock LS input. For what it's worth, I found one anecdotal piece of evidence to back this up. One guy had his Viper input machined down to the size of an LS input, and he said that the machine shop had to order a stronger bit to get through the steel of the Viper input. Still, I wouldn't really sweat the strength difference between the LS and Viper input with something like an LS3.

One other bit of info I wanted to pass on to you is the trans fluid for the Viper T56. There are stickers all over mine that warn against using anything other than the Chrysler specific Castrol Syntorq LT. It turns out this is pretty much a "quieter running" version of the AC Delco 10-4059 and rebranded GM 12346190 that most people run in the F-body LS T56s. Both of those will work, and are cheaper and easier to find.

I studied the info sheets and the only fluid I could find that claimed to be a "direct" replacement for the Viper is Redline MT-85. That's what I went with and the trans is quiet and shifts great.

Whatever fluid you do go with, make sure it is a GL-4, and you'll need 4 quarts....or 5 if you know you'll spill a bunch like me...lol

All of the info above works for the newer Viper T56s (2000-ish to 2006-ish) I'm pretty sure the fluid is different in the older 1990's Viper T56s.

[AU Doc]

can you point me to a link for that McLeod kit? I've been able to
Find the separate pieces, but not the entire kit.

Right now the plan is to get an adapter to mate the trans to a Muncie bell. Then I can keep the viper input.

Any advice on a good crossmember?

[AU Doc]

Now that I think about it, if I'm going to be using a stock bell, then I might be better off with a mechanical linkage setup.

[CliffsBlueCamaro]

That's exactly what I would do. I've been giving more serious thought to going LS lately, and I keep coming back to the same idea for the same reasons - keeping the viper input and keeping mechanical linkage.

There isn't really a "kit" out there, but if you give me some time I can get you all the part numbers I was planning on using.

I used the adjustable cross-member from BMR and it worked perfectly. --> http://www.bmrsuspension.com/?page=p...productid=1027

[AU Doc]

Here she is! Any idea how to identify which year viper it's out of?

[AU Doc]

Another Viper T56 specific question. Since this trans will sit back a little further due to the input shaft length, will I need to do any trans tunnel surgery?

I'm waiting on suspension parts now, but once I get my suspension sorted the transmission is the next project I'm planning to tackle.

[AU Doc]

I'm getting close to tying finishing up my suspension upgrades. I'm hoping I can pull my transmission apart this week in the evenings to see what I've got. I'm hoping it won't need anything, though I'll probably go ahead and upgrade the synchs and keys. I've never built a manual before, so again I'm hoping it won't be too bad.

Any thoughts on issues I should be looking for?

[Craig@Bowler]

I'm getting close to tying finishing up my suspension upgrades. I'm hoping I can pull my transmission apart this week in the evenings to see what I've got. I'm hoping it won't need anything, though I'll probably go ahead and upgrade the synchs and keys. I've never built a manual before, so again I'm hoping it won't be too bad.

Any thoughts on issues I should be looking for?

I would first check to see if you have any metallic residue in the bottom of the case when you open it up. Thats a good sign that you need to look for damage because likely you will find it pretty quick. If you're all good there and it's just old fluid then closely look at the gears to see how they're wearing or to be sure there's not chips, chunks, etc. that will keep you from having a nice shifting transmission. After that you just need to decide how deep into parts replacement you want to get.

[AU Doc]

Thanks for the info! So far things are looking good. I got the tail housing off, and the magnets didn't seem to have any metallic residue. I expected there to at least be the fine metal powder, but nothing but fluid.

No obvious signs of wear on the gears, yet. Though reverse is about all I can see well at this point, and I don't imagine it gets a lot or work

Any advice on how far I should go assuming everything looks good? I figured synchros, fork pads, keys, lock rings, and seals since I've got it apart. Anything else I should replace while I'm at it? Any bearings that should be replaced?

I need to get some better lock-ring pliers and I'm going to have to modify my gear puller to reach the speed sensor, much less 5-6 .

[AU Doc]

I'm trying not to get excited prematurely, but I think i can still see tooling marks on the gears with no signs of a wear pattern. I'm guessing that would mean extremely low miles?

Any suggestions on what to look for regarding bearing damage?

[CliffsBlueCamaro]

Here she is! Any idea how to identify which year viper it's out of?

I think you've got a pre-2000 one since it is a Borg-Warner and not a Tremec.

Did you decide if you are going LS or are you sticking with the SBC for now?

[AU Doc]

Right now I'm planning to go with the SBC and a mechanical linkage setup. Trying to keep it as cheap as possible.

[AU Doc]

A little bad news on the transmission front. The 5/6 gear pulled off the shaft without a puller. I didn't think much of it at the time, but after a little reading this is apparently a common issue that causes vibrations in 5/6. Shafts are in short supply these days, so I'm going to send it Texas to have it built up and remachined for a tighter fit.

I still need to get 2nd gear of the shaft and really inspect things closely. On the surface everything else looks great. I'm hoping the 5/6 gear is the only issue I run into.