The Stovebolt Site Forums The Shop Area Engine Shop new tans won't go in all the way

Just got a new trans for my 51 3100 216 motor. While trying to install it i can't get it to go that last inch.. I used the shaft from the ols trans to use as a clutch realinment tool is there somthing Im missing?

Three things to think about:
Input shaft not going into pilot bearing (measure and ensure it's the right bearing),
Splines not lined up between shaft and clutch (put trans in gear and wiggle output shaft while mating the trans to the engine),
And last, make sure the bearing retainer on the trans will fit through the hole in the bell housing. (this should only affect the last 1/4 inch.
Is the new trans the same as the old one? Or is it an upgrade?

is it possible I have the trowout bearing backwards?

same as the old one and smae bearing

Check size of hole in pilot bushing to diameter of pilot on input shaft; check if the throw out bearing collar will slide freely on the trans snout (front bearing retainer); see if the clutch plate slides freely on the input shaft splines; measure from the pilot bushing to the bell housing face and also from the front of the input shaft splines to the trans face---these measurements won't be exactly the same but they won't be off by an INCH.

Just give up on it for a day and try again the next day. Stabbing a transmission can be a 5 minute or a 5 hour affair.

thanks for the input guys

Grin Atthelid, be sure your "gap" is only one inch, not more. If so, your problem is at the pilot bearing, with one exception.

Most common problem is too much weight "hanging" on your clutch disc. Rear of your trans moves downward, input shaft moves upward. Only takes 1/32 of an inch to hang up on your pilot bearing. You mention a correct pilot bearing, so no problem.

Although many use an old transmission input shaft for clutch disk alignment, this often causes this problem. A steel input shaft is just heavy enough to tilt a bit; your arm gets tired. Should you plug in the steel shaft then let go to bolt down your pressure plate, you will be out of alignment because of the weight of the steel input shaft.

Best to use one of those lightweight plastic alignment shafts.

Use a transmission jack with wheels to install your trans rather than bench press it into place. This supports the weight and you can easily make adjustments, like the tilt, by slipping thin pieces of wood or whatever, under the front or rear of your trans. Easy to roll a trans side-to-side with a wheeled trans jack, your right and left alignment.

A true must is to use extra long bolts temporarily, like 4 to 6 inch bolts. Get your trans up there, get it started in, work on alignment. When 2 or 3 inches to go, thread in long bolts, top holes, as if you are bolting your trans in place. Snug, not tight, snug those bolts up in the holes, good thread depth so those bolts will not let loose. This will help keep your transmission in alignment. For your old 216 bellhousing, you probably will only be able to install the two top bolts. Might be able to squeeze in 2 inch bottom bolts, maybe 2 1/2 inch bolts from inside the bellhousing, if you have tiny nimble fingers. However, remember those bottom bolts will push into the bellhousing as you insert your trans; might not be able to withdraw those bottom bolts!

Your wife has tiny nimble fingers. She probably would not mind crawling around on cold concrete under your truck. Kids love to do this, maybe a kid.

A last ditch effort is to hook up your clutch pedal linkage then depress your clutch pedal to the floor and jam with a stick between your pedal and seat frame. This will not free your clutch disc but will allow you to move the disc around if you jam in your spare steel input shaft. Might get lucky.

Final effort, loosen off your pressure plate then realign your disk using a plastic input shaft device, available at parts stores. Be sure to axle grease the pilot bearing end to get some grease up in there, not too much grease, just a little. Not needed if you have already greased the pilot bearing.

My exception mentioned is if you mistakenly installed a "long" throwout bearing instead of short. Not sure on your truck if you need the long or short, I think short. Difference between a long and short bearing is about an inch.

Again, use a wheeled transmission jack, go buy a jack if you do not have one, a must have. Thread in long guide bolts up top. Depress your clutch pedal to release some grip on the disc. Loosen your pressure plate, realign.

Concept here is support the weight of your trans with a wheeled jack and guide bolts so you can use your muscles for delicate alignment. Much easier job this way, and you are less likely to end up with a tailshaft stabbed clean through your head.

Bet you a buck a trans jack and those guide bolts will do the trick for you, and maybe a kid to supervise you under your truck.

Billyray

Many years ago, I had a 1955 2nd series with a 283 that somebody had put a 2 speed power glide in it.
I found a nice 4-speed floor shifter and all of the pedals clutch etc.
Dropped the old 2 speed out no problem, but had the same problem as what you describe.
That last inch was a no-go. You do not mention as to what trans came out of your truck to start.

As Highflyer said, and everyone else, check your pilot bearing. The inside diameter of my 55 2nd was smaller than the diameter of my output shaft on the 4-speed.
It looked right, but oh no it was not.

Billyray,
I wish my shop manual was as descriptive as you are in mating a trans to an engine. Very well stated.

I could not agree more as with crenwelge, there is something about just stopping, cleaning up, put your tools back and calling it a day. Give your truck a overnight break. The next days has been some of my best wrench turning experiences.

Dale

I was able to mate my engine with the new trans after a good nights sleep depressing the clutch with the trans floor cover off and wiggling in the spare shaft. But much like billray said as soon as I had the weight of the trans in there the cluth slipped again. so with a calm head and a few beers in me I reset up, used a floor jack to suport the weight. It put up a fight but I got it to slip in with enuf force to get my finger piched. No pain no gain, its all together. Got the chance to pull it out of the shop and shift it in and out a few times grining the whole time. Still sloppy in the tree shifting but it will do tell i can replace the shift box unless you guys have any ideas how to get that to straiten out. well in the process of testing out the truck in the drivway i noticed the water pump was leaking from the center bearing so thats this weekends project not that it will take that long but hopfully I will be able to start fitting sheet metal afterwards.

Good on ya for being patient enough to solve the problem. Any trans the size of a SM-420 or bigger definitely needs some sort of support as you're installing it, for safety reasons as well as ease of installation. Here's a little trick I've used successfully all the way up to big rig trasnsmissions- - - - - -put a long piece of heavy wood like a pressure-treated 4X4 landscape timber, or even a 6X6 through both windows, padded with rags if you don't want to scratch up a nice paint job, and hang the trans from a cable come-along. You can make very accurate height adjustments by using the ratchet on the come-along, and there's enough fore-aft swing with the cable to let you stab the input shaft safely.
Jerry

Grin Atthelid comments, "It put up a fight but I got it to slip in with enuf force to get my finger piched."

Congratulations! You have earned your "Pinched Finger" merit badge! Wear your badge proudly!

Maybe work on your "Stuck Arm" merit badge next. A good place to start is weaving your arm like a pretzel over your exhaust pipe, under your master cylinder, over your clutch linkage, then up and around your bellhousing in a feeble attempt to break loose a bolt you cannot reach from above. When you try to pull your arm out, bound to be a sharp cotter pin or a pointy spring end which will bury into your forearm like a fish hook. Stuck Arm!

Taking apart your steering column shifter box will earn you a "Chinese Puzzle Box" merit badge.

Delay earning your "Forehead Knot" merit badge, that one really hurts and you will feel stupid after whacking your forehead with a one pound ball peen hammer.

Good to read your transmission is in and working.

Billyray

hit the pilot bearing all the way IN !!!!!!!!!