Hard shifting
 

I installed a McLeod pro street clutch and alum FW, I was certain I got the Lakewood bell dialed in correctly, but toploader with 5K mile rebuild is hard to get into any gear especially 4th at high speed and RPM. Before this the trans shifted good. Is there a way to pull trans but not bell and clutch to check it again?

It depends on your frame, transmission mount and access. On my SPF I have to pull the tunnel cover off to gain access from above in order to remove the driveshaft and get at some of the bolts mounting the transmission to the bell housing. Which for my car means removing the seats as well.

as others have stated in prior threads and I have used myself, get either threaded rod or extra long bolts with their heads cut off. I have several different lengths that I use, up to 12" long. Take one bolt out at a time and replace it with a threaded rod/bolt with head cut off. When you are done you can then slide the transmission back out of the pilot bearing and clutch. Use this method to reinstall the transmission (reverse order).

What type shifter do you have in the car? It’s hard to be certain from your description but I would suspect the shifter needs to be adjusted so that the neutral gate is aligned correctly. If the transmission shifted cleanly before then it should still unless the shift linkage is misaligned. Just unbolting it and re-bolting it back to the transmission, even if care is taken to not change any of the rods, can cause subtle changes in the neutral gate alignment that will create shifting issues.

My input is based on 20 year old memories and a few photos I took while I had the car apart, but here goes. .. My EM had a Richmond 5-spd transmission, removable transmission mount and C4 Corvette rear end. I pulled the transmission with bell housing attached several times while chasing a leaky HTOB problem. I don't recall pulling the transmission without the bell housing. .. Based on my photos, it appears that if I disconnected and removed the transmission support and driveshaft, it might be possible to slide the transmission back far enough to disengage from the clutch. The two obvious problems from my photos are the shifter clearing the hole in the tunnel, and the safety hoop that surrounded the driveshaft. I don't recall if the hoop could be removed. To clear those obstructions it might be necessary to tilt the aft end of the transmission down and I don't have a good idea how to do that without a lot of extra work at the engine. .. Good luck.

my car has a very heavy clutch, check your slave cylinder.proper alignment and make sure you bleed it hope this helps.

What clearance did you set for your disc to flywheel air gap when the clutch is released?

You should be using 0.020" to 0.025".If you set it up for less, the trans will be all but impossible to shift especially once the clutch heats up. More and you will begin to experience clutch slip depending on your pressure plate load and the disc friction material.


Ed

I am sorry I wasn’t clear enough, I can remove the trans I want to check bell alignment before removing bell and clutch to see if it’s out of spec and that is causing hard shifting, maybe a vise grip on diaphragm finger for dial indicator to mount? Hurst competition plus just replaced bushings with bronz ones and adjusted linkage, no change. I am using an internal HTOB how do you aligne that? my gap between it and diaphragm fingers is .092 . I am using a single disc clutch and never heard of a needed air gap, what do you shim the PP?

What make is your HTOB? Different manufacturers have different gap requirements between the HTOB and the fingers of the pressure plate. You have to put a straight edge across the back of the bell housing and measure the distance to the fingers. Most of the instructions then require you to take a measurement from the face of the transmission to the leading edge of the HTOB and then have you set the HTOB so that the distance between it and the fingers are in an acceptable range.

If you do not have the instruction sheet, depending on the manufacturer I may have one that I can scan.

Just to clarify......you say "installed", does this mean installed newly purchased different bell housing and throwout bearing as well? In other words, Did you have something different before or what has changed?

New clutch,FW and tilton 6100 bearing which calls for.100- .150 clearance between HTOB and diaphragm fingers. The most I could get was .092. Lakewood I was using before. BTW thank all you guys for taking your time to help

The HTOB clearance may be your issue. They do not operate well outside of the required clearances. I tried to use a Tilton HTOB on my top loader and ended up returning it unused as I could not get the proper clearance. I went with a McLeod HTOB, which I had on the previous build and that has worked. If you try going to the McLeod you will have to remove the inner adjustment ring and then thread the HTOB onto the threaded portion of the housing around the input shaft more than likely. The pain with the McLeod is that there is no locking mechanism to stop it from rotating on the shaft. so you have to be careful to keep it in the right position when installing the transmission. A minor pain and doable. The options for HTOB's for top loaders are not as prevalent as they used to be.

I guess in a nut shell is there a way to mount the dial indicator without and before removing the BH and clutch?

Did you have shifting problems before R&R the clutch/FW? Not that you shouldn't verify the alignment of your bellhousing but if it worked before what do you thing changed on the BH now?

Google indexing a bellhousing or try the search here. I recall Kirkham had a pretty good procedure that someone posted here a while ago.

Was the pilot bearing/bushing inspected or replaced?

I haven't tried, but I suspect, it you pull the trans and set up your dial indicator on the clutch, you will be able to check runout.

As others have suggested, I would think other items are more likely. Also, the need for low runout is because modern transmissions use tappered bearings. I think a toploader has ball bearings and wouldn't require as low of a runout number.

John

True - and bellhousing runout usually generates issues such as kicking out of gear as the motor is reved up and eventually component wear and failure over time - not so sure about shifting issues. I would try to cut down on pedal free play to ensure you are getting full disc disengagement in neutral and on shifts. And as someone said - make sure the hydraulics are free of air.

I’m guessing you are convinced it’s not a shifter alignment issue. Never tried to check alignment of a bell housing with the clutch in. But if you have a sufficient sized magnetic base that will anchor solidly to the clutch fingers then you should be able to do so.

5k miles ago when I built it I thought I had the BH dialed in and it shifted fine, but when I just changed the clutch the BH was out of alignment I didn’t make a note of how much and the pilot bush should be .67 ID it was enlarged pretty evenly around to about .90 . I did change the bushing. Yes I am sure about shifter linkage alignment. But you guys are good and I am going to bleed system for a 4th time. Much easier than pulling the clutch. Thanks again

The pilot bush wore from .670 to .900? That's .230 or nearly 1/4 inch of enlargement. A pilot bush wearing like that would have been the cause of your difficult gear selection, especially from rest, 1st or reverse.

I agree but that’s the old bushing that was in there before the new clutch and it shifted fine. Thanks to you all I am not as concerned about BH alignment. After bleeding I am going to try to get a feeler gauge between clutch disc and FW with clutch disengaged.

If your bell housing has not changed since the previous clutch install then your alignment is no different than your last install. Additionally, worth some consideration, is the fact that if the BH was misaligned the effect of the misalignment is the engagement of gear teeth between the input and the countershaft.

The difficulty in engaging fourth gear does sound like a misalignment problem. The challenges in engaging other gears sounds like a clutch air gap problem where the air gap is too small and the disc drags on the flywheel or pressure plate or both.

A significant misalignment will cause premature tooth wear on the input and countershaft. If you drag race the car with sticky tires then the possibility of breaking teeth off the input and/or countershaft is there during hard launches.

If this is a new bell housing then you need to align it with the transmission out and the pressure plate and disc out. Mount the dial indicator to the flywheel and check the alignment. Do not use the Lakewood alignment dowels. You will go crazy and give up. Here is a thread on how to properly do the alignment, click here => Bell Housing Alignment

I have attached a page out of the Mcleod instructions for their Street Twins with their commentary about air gap highlighted in yellow. I built my own twin disc clutch and flywheel but used the McLeod guidelines for air gap. I think you will be happy with them also. If you feel a bit uncomfortable call your clutch manufacturer and ask them what they recommend for air gap.

Whenever the disc(s) drag on the flywheel or the pressure plate you will have significant difficulty in shifting if it is possible at all. If your clutch linkage does not fully disengage the pressure plate then you need to fix it. If it does and you still have drag then you need to get the air gap back into spec.


Ed

BH is original and I aligned it this time with Robb Mc dowel pins. I don’t drag race. I am going to bleed again, I have a single disc should I have at least.020 air gap as well? Thanks for all the info you have provided