GS Racing

I need a T56 and have been offered two at the moment (usually really hard to come by here), both selllers claim they are LS fitment, but they 'would' say that as they know thats what will sell...

I know LT ones, and pretty much all, have various differences, input shaft etc, so when I go take a look at these boxes, are there any numbers or measurments (input shaft maybe?) I can do to 100% be sure its an LS one and not from something else?
(im in the UK and these transmissions were fitted to Aston Martins, Lotus Carltons, etc, as well as the various imported LT engine things etc)

Any help appreciated

silplu83

iTrader: (5)

The LS1 has a longer input shaft than the LT1 but I'm not sure of the measurements.

thesource

iTrader: (60)

LT1 unit has a collar on the front of it where the input shaft sticks out of the unit.

YellowB4Z

iTrader: (9)

LT1 has a 2x3" hole in the side of the front plate for the shift fork and the LS1 had 2 small 1"x1" holes for the clutch hydraulics. The LS1 also has a raise ring around the input shaft with 2 small tapped holes to mount the slave cylinder.

GS Racing

Good info, hopefully I can translate this in to what I am looking at.
I dont suppose anyone has pics so I can visually see the difference?

He says its a magnesium LS bellhousing as it was off an LS3 mounted in a spaceframe chassis.

Here is a pic-


Look like an LS T56 and B/H to you?

silplu83

iTrader: (5)

No that looks like a LT1. See the hole with the two studs coming out? Thats where the LT1 slave cylinder goes.

Was this part a joke:

GS Racing

Honestly, thats what he was saying, I wasnt so sure going by the only pics ive seen, so I thought I best ask the experts??!

The LS3 and spaceframe was believable enough, the UK is full of v8 engine kit cars.

LSs are much much more common than LTs in the UK though you see... hmm

GS Racing

Oh, reading the above reply again, do you mean thats where the LT1 manual clutch fork goes, and LS1s dont have that hole?

Mike454SS

iTrader: (4)

Correct, the part closest to the red thing on the floor where those 2 studs stick out, is where an LT1 cars slave cylinder would mount. The LT1 uses a pull style clutch, so there's a fork that goes from that slave to the center of the transmission, mounted on a pivot, so when the slave cylinder pushes towards the engine, the fork pulls the clutch back. The LS1 T56 uses a push clutch, so it has a cylindrical slave cylinder mounted over the input shaft that simply pushes the clutch towards the engine.

For what it's worth, even in an LT1 application, that transmission is missing a spacer piece off of the bellhousing that would allow the LT1 hydraulics to work in the first place. Without that, an LT1 car can't use that bellhousing/trans either.

thesource

iTrader: (60)

Thats an LT1 unit.

GS Racing

Ok, so thats that one forgot about then. Thanks for the info

I know of another, no bellhousing. Does anyone know the input shaft lengths, or know of other distinguishing features, with pics if poss, that will determine the one without a bellhousing is 100% an LS T56?

A collar is mentioned above, but mentioned for LS and LT, so its confused me...?

GS Racing

Right, as it may help confirm things (ie that its not just an LS with an LT bellhousing or whatever), I have some better pics, inc input shaft...






Also, can anyone tell me, in comparison to that pic (if thats an LT input), the difference between that and an LS one, so I can look out for the correct one.

Is the collar mentioned what you san see on that input shaft, ie the splines only go halfway then the collar over the top? And LS ones are a single piece of metal?

Thankyou!

Billy M

LT input length: 9-1/4"

LS input length: 10-5/8"

Gen414

iTrader: (38)

Here is a front shot of a LS based T56...can you see the differences in the LT T56 pic you provided? If not, look @ input shaft...see the mounting bolt holes for teh slave (on my pic of teh LS '56, and look at your LT, the bolt holes are not there)






Edit: I am not sure whose picture this is...I "stole" it from somewhere....

GS Racing

Gen414, perfect pic, I searched for one and found one, but not as good as that one- thankyou! Lets hope the 2nd one ive been offered really is one...!

Gen414

iTrader: (38)

Here are 2 side by side shots....


LS T56, without bellhousing, but still has midplate attached:





LT T56, with bellhousing:




And, you are welcome by the way, anytime.




Edit: These pics were taken in my garage at my house, and NOT my shop. My shop is cleaner......haha