The Stovebolt Site Forums The Shop Area The HiPo Shop T-5... again...

I think I already know the answer to this and why I didn't do it in the first place is a mystery...

I have the T-5 installed (again) but the clutch disc will not completely disengage from the flywheel. With the back wheels off the ground, the truck in gear, and the clutch pedal pressed in (adjusted to where there is no play in the pedal at all) the tires spin and if you push in the brake it will kill the motor. Is this the drag several of you have mentioned? Do I need to lengthen the splines on the mainshaft? I can see that the pressure plate and clutch move... I can fit the very tip of a flat screwdriver inbetween the clutch and the flywheel when the clutch pedal is pushed in.

Starting to get frustrated and really want to have the truck going by the end of next week.

How about between the clutch presure plate & clutch disc. Can you put the screwdriver in there? Is your pilot bearing back far enough in the crank. That,s the problem I had. When I pulled it back out I could see on the front of the bushing it was rubbing the tran shaft. I cut the grooves out a little before I started. It works beautiful. I think that is your problem.

Hey Josh,

Check your email.....

Dave

Thanks guys. I will check the pilot bearing when I pull the transmission later this week to lengthen the splines.

Ahhh... Hindsight is always 20/20. When I cut the bearing retainer and mainshaft I thought to myself "What about lengthening the splines... That was mentioned on the Stovebolt... *long pause* Is that Chuck Norris over there? Awesome!" I hate it when I get distracted.

I am stumped! I lengthened the splines, checked the pilot bearing, put it all back together and... nothing changed! I guess it is a little better... Stepping on the brakes doesn't kill the motor anymore... it just slows it down. So... any suggestions?

I think that I am going to have to pull the transmission and lengthen the splines further. Guess that is what you get when you let the bearing retainer and large grinding disc dictate how much you cut. I will pull the clutch disc and pressure plate to check clearance and measure the mainshaft and bearing retainer to compare to the original transmission. The problem has to be here. If I am overlooking something please let me know.

Going on vacation Friday without Miss Anne Thropy. She can sit and wait for three weeks until I have time to work on her again. Just lost all sorts of cool points with my friends though. Gonna have to take my Nissan Sentra... yuck!

So, what cluth disc are you using? And are you using the original pressure plate? You shouldn't need to lengthen the splines.
MONGO

jthuma... i put a t-5 in my '42 1/2 PU...bought it directly from Langdon stovebolt...all I had to do was relieve (light grinding) the inside diameter of the clutch plate fingers so it slid all the way up the spline. If your still stuck call Tom Langdon at Stovebolt, he's very good at these trannies.

KCMONGO - I am using a 9/18" 14 spline 1" clutch disc (RCF-4190) with the original pressure plate and throwout bearing/fork.

Steveg - I have not looked at the pressure plate (clutch cover) fingers for clearance. What do you mean by "so it slid all the way up the spline"? Are you referring to the clutch disc?

Yup, that's the setup I'm using, are you sure you cut the bearing retainer far enough back? Did you use the make it match your old transmission method?
Mongo

I did. I should probably pull the transmission again and check the measurements.

From what everyone is saying the transmission should be working. I am thoroughly stumped and I am sure it is something simple. Is it possible it is in the linkage?

after you pull it you will probably see the scrapings where it has been hanging up.

I sent an e-mail to KCMONGO on this. Is the easy solution to use the Vega disc recommended by Robert French in the Tech Tips? It seems to me that the problem is clutch disc travel. The measurements should be the same as the original transmission. It slides in without any hang ups to the bell housing and bolts right into place. This is on a 52 with a foot pedal starter so it has the original pre-53 flywheel. I am going to order one and check it out.

Had the same problem when I helped my son install a T5 in his '60 Burb. We ended up putting a 1/8" shim between the transmission and bell housing.
We would have used washers but didn't have the right size at 11:30 pm :mad: .
But that's how we solved the problem

Sounds like the problem is that the splines do not extend far enough for the clutch disc to fully disengage. I think there are three possible solutions.

1. Get a clutch disc with a 'shorter' hub, or grind down the hub on your disc so the engine side is 'shorter'

2. Shim the tranny out a little so your clutch disc doesn't foul on the tranny end of the splines.

3. lengthen the splines/clean them up with a cut off wheel or file. You shouldn't need to do too much- 1/8th or 1/4 of an inch maybe? Alot of that is just deepening/widening existing spline grooves becuase they get narrower and shallower towards the end where the clutch disc is sticking/stopping.

One way to tell for sure if this is the problem is to lie under the truck with the clutch cover in a spot that you can see through. Have someone step on the clutch pedal and observe. If there pressure plate is fully disengaged but the clutch disc isn't its probably the splines. You could also put in the tranny with the clutch disc and no pressure plate to see if there are splines behind the clutch disc so that it can disengage.

I tried step 3... couldn't get much off with a 4" disc without removing the bearing retainer so I probably did not get enough to make much of a difference.

Step 2 just scares me a little... I have already cut the bearing retainer and main shaft to the same dimensions as the original transmission and adding some washers as spacers as a permanent fix is just not right. I could see a plate but that would require some time on the plasma table at work.

I am on to step 1 now... gonna try a late 80s Camaro disc and an early 70s Vega disc to see if the shorter hub will help. This seems like the best route. Gonna take the original 10 spline down to compare hub length.

When you cut down the original input bearing retainer shaft did you compare the spline length of the original tranny and the t-5?

If you want to lenghten those splines just pull the bearing retainer, lengthen them, and put it back on. I think its only four bolts...

good luck!

jt- I'm not sure if you solved this problem yet or not but I had to lengthen my spline cuts as well. My bearing retainer was gooped on with silicone and I didn't want to break the seal and remove it, so my angle grinder wouldn't fit in. I used the "poor man's" dremel tool that I had bought from Harbor Freight for $20.00. It took longer that the grinder would have but it worked fine.

For those of you "extending" the splines on the T5 mainshaft....you should remove the throwout pilot shaft (4 bolts) and use a "high speed" air cut-off tool...with a thin (1/16"X 3") cutoff wheel. Using a 4" angle grinder is going to be way-too-much for this surgical procedure. A Dremel would be better than an angle grinder!!!!

Then, MOST IMPORTANTLY....take the disc you are going to use and slide it onto the splines to verify that you have actually increased the amount of movement. It's not how much you take it off...it's where it comes off and if it INCREASES THE TRAVEL. This is a critical step to getting it right the first time.

If you've just got to slap it together without checking the disc...look up from below the flywheel sheetmetal cover and you'll be able to see if you've cut enough when someone depresses the clutch. Put it into gear, turn the output shaft by hand and make sure there is no drag.

Check my pics as my is driven every day. Hope this helps!

I've had a similar problem. I'm not sure if this applies or not but twice I have installed a new clutch disk and later found out the disk was too large in diameter. The disk would hang up on the flywheel where the outer edge of the clutch disk meets the recess for mating surface of the flywheel. Does that make sense? Some flywheels have a recessed surface for the disk (1/4" or so?). Had to pull the T-5 out of the S-15 again and check it. Should have fit the disk first and would have seen the problem.
I don't know if this is a clutch disk remanufacturing flaw or what. But now I check it first to save a lot of headaches.
We live, we learn.
Rick

I had the same problem as jthuma94 described.I pulled the transmission and grinded a little on the splines.I reinstalled the tranny,same problem.I pulled the tranny back out and decided the hub on the clutch disk was too tall.I ground down the hubs surface where the splines are.I Made sure that i was grinding the side that slides to the transmission.Then i knocked off all burrs and sharp edges the grinder left on the hub.I reinstalled it,it shifts like a dream.

Sweet! Home from vacation and one hell of a first week back at work and now am ready to tear into this again. I am going to check all the measurements, pull the bearing retainer and lengthen the splines, and put it back together. I have three clutch discs to try and I will put in the shortest (hub length) one. If this does not work I guess I will be grinding on the hub. I will post an update later this week.

I went through this as well. For all measuring, you need to be consistent. I used the face of the bell housing as the reference point for all dimensions.

Once you pull the tranny, measure the distance from the hub of the clutch to the bell housing face. Then give yourself 1/4"-3/16" for clutch disk travel, (i.e. subtract that amount from the previous dimension). Then grind your spline and use one of your disks and put it on the spline. Make sure that, when pushed all the way on the spline, the dimension between the hub of the disk and the mounting surface of the tranny, (which will end up at the same point as the bell housing surface)does not exceed the allowable dimension that you have previously determined. I had to keep grinding bit by bit until I had more than enough clearance, since I didn't want to hoist the tranny in any more than I had to.

All works great.