TKO 600 Grinding.

[jhv48]

Here we go again, but this time a slightly different transmission problem. Car now has 4300 miles on it.

Symptoms: Very hard to engage first gear when hot, unless car is moving forward slightly, then it drops right in. And here is the newest wrinkle: The trans now grinds sometimes (you can feel it through the shifter, but you can't hear it) when you are pulling the lever OUT of one gear BEFORE it goes into another gear with the clutch depressed. Does it in any upshift at times, but not always. You can feel the grinding through the lever. Something is grinding, but not loud like when you miss a shift. Yet, sometimes the trans shifts smooth as glass. But lately it is getting worse. Downshifting is smooth and noise free. Car will not creep if in gear and clutch depressed.

I have done all of the following:
1, changed, bled the brake slave and fluid.
2. The clutch is adjusted to disengage fully about two inches from the floor. Have tried different adjustments.
3. The rear tires will spin freely if the car is in gear and the clutch depressed while engine off.
4. Reverse will NOT grind if you slowly engage it hot or cold after shifting into another gear first.
5. Replaced the trans fluid with GM Synchromesh.
6. Clutch and trans were removed and declared fit by both clutch and trans experts about 2000 miles ago when tranny ground every time you put it in reverse..

The last time (at 2500 miles) it got hard to shift, and it ground every time in reverse, we replaced the pilot bearing and everything was rosey for about 1500 miles. Now it is slowly getting worse again.

I'm beginning to think I should just drive it till something breaks and then we will know what it is.

Thoughts? I need creative solutions. And remember, the problems disappeared after we replaced only the pilot bushing last time. I just can't believe it is that again, and, if it is, why so soon and how do we prevent it from happening again? And what is causing that grinding feeling through the shift lever on upshifts? Wouldn't the synchros eliminate that? There is no synchro grinding on downshifting at all.

This particular installer does all the local installations for Hillbank in Irvine and they have never seen this happen before. They used the same parts on all their SPF and CSX installations. Mine is the only one with a problem.

[ERA Chas]

I'm grasping that the nose of the input shaft is too long, putting stress from the crank to the tailshaft-causing the tight feel. Maybe a .030" to .050" cut off the nose?

I know it's painful to suggest a trans R & R for such a diagnosis...

[elmariachi]

Is it a grinding, or could it be a vibration? I experienced these exact symptoms shortly after getting my car on the road at 1300 miles and it turned out to be a sloppy pilot bushing transmitting a gritty, course vibration through the shifter. As I rev'd up through the top of first and prepared to shift, it felt like gears were grinding. Even though we dialed the Lakewood in twice with two sets of eyes, it was clearly not in spec. When we pulled the tranny to repair the pan leak at 3k miles, we found a badly worn pilot bushing. So we dialed the Lakewood in AGAIN and replaced the bushing and all was fine instantly. I just passed 4k miles and although I don't have the gritty vibration again yet, I can tell the pilot bushing is getting sloppy again because of how it grabs and pulsates sometimes in reverse. I am convinced the crappy tolerances of the Lakewood and our inability to get it dialed in is wallowing out the bushing, so the Lakewood is going in the dumpster in favor of a Quicktime at some point. Sorry I can't offer more advice.

BTW, which bellhousing are you using?

[blykins]

Was the bellhousing dialed in?

[jhv48]

Originally Posted by elmariachi

Is it a grinding, or could it be a vibration? I experienced these exact symptoms shortly after getting my car on the road at 1300 miles and it turned out to be a sloppy pilot bushing transmitting a gritty, course vibration through the shifter. As I rev'd up through the top of first and prepared to shift, it felt like gears were grinding. Even though we dialed the Lakewood in twice with two sets of eyes, it was clearly not in spec. When we pulled the tranny to repair the pan leak at 3k miles, we found a badly worn pilot bushing. So we dialed the Lakewood in AGAIN and replaced the bushing and all was fine instantly. I just passed 4k miles and although I don't have the gritty vibration again yet, I can tell the pilot bushing is getting sloppy again because of how it grabs and pulsates sometimes in reverse. I am convinced the crappy tolerances of the Lakewood and our inability to get it dialed in is wallowing out the bushing, so the Lakewood is going in the dumpster in favor of a Quicktime at some point. Sorry I can't offer more advice.

BTW, which bellhousing are you using?

I think we have a winner. It feels like grinding but could easily be a gritty vibration. But, I have a Quicktime bell housing right now. So, how do you eliminate the pilot bushing failure problem? Dialing in the tranny has been done twice, and both times the bushing has failed in 2000 miles. And each time it is costing me about $1000.

[strictlypersonl]

I would check two things:

Is the face of the bellhousing parallel to the block face? You'll have to move the flywheel-mounted dial indicator so that it measures the distance from the flywheel to the mounting face. (Watch out for crankshaft end play!)

As Chas said, is the transmission input shaft too long?

[elmariachi]

Originally Posted by strictlypersonl

Is the face of the bellhousing parallel to the block face? As Chas said, is the transmission input shaft too long?

I don't have the spec handly but it seems that my parallel differential was what I thought would be negligible, like maybe .008.- 012??

In my case, the input shaft was too long upon first assembly so we removed the shaft, had it prefessionally machined the right length and reinstalled. So its not that.

Sad to hear however that the QT is no better. I guess I'll spend that $700 on something else. Like tequila.

[jhv48]

I guess it's time to take it in for some exploratory surgery again.

The installer told me he dialed in the bell housing, but he probably didn't check it for being perfectly flat against the block or transmission.

He is obviously missing something. Now to convince him to do the job right.

[ERA Chas]

Originally Posted by jhv48

I guess it's time to take it in for some exploratory surgery again.

He is obviously missing something. Now to convince him to do the job right.

Make sure the nose of the input shaft is inspected for wear or abuse. Measuring the distance from the mounting flange into the pilot hole and comparing to the distance from the trans face to the shaft nose will confirm if that's the problem.

[Rick Parker]

I had a machinist point out once that the block mounting face of the Bellhousing I had was not perfectly parallel with the transmission mounting surface, it was off about .008 as I recall. Mounted it in a surface grinder and after several passes it was brought into spec.

[eschaider]

Originally Posted by jhv48

I guess it's time to take it in for some exploratory surgery again.

The installer told me he dialed in the bell housing, but he probably didn't check it for being perfectly flat against the block or transmission.

He is obviously missing something. Now to convince him to do the job right.

jhv48,

Assuming the input shaft does not bottom out against the crank, I suspect your problem is what several of the guys have already identified - block/bellhousing alignment.

Using the offset dowels to align the bellhousing bore with the crank is difficult at best. It is far better to drill out the dowel pin holes a sixteenth or so, then lightly snug the bellhousing to the block, align it to the crank center and slide two, reamed to size, thick steel washers over the alignment dowels. Weld them to your bell housing and you are done - forever on this block.

The parallelism issue is easily solved as I think Blykins pointed out at a machine shop. A light cut (just adequate to clean up the transmission mounting surface) will permanently correct any parallelism issues.

A misalignment of 1˚ (which is admittedly a giant misalignment) with your crank center line will produce an offset of 0.0175" per inch of bellhousing depth. So a seven inch deep can with one degree of misalignment will have an offset at the pilot bearing of 7 x 0.0175" or 0.1225"! Correct can alignment is a big thing. Take the time to do it right.

Ed

[madmaxx]

Go pick up a stock ford aluminium bell housing and install. I have never heard of an issue with a stock bellhousing, am I just lucky or does the generic stuff work the best.

[elmariachi]

Originally Posted by madmaxx

Go pick up a stock ford aluminium bell housing and install. I have never heard of an issue with a stock bellhousing, am I just lucky or does the generic stuff work the best.

No way in hell I am running a high performance engine into a TKO 600 through a stock bellhousing.

[Excaliber]

Why would a stock bell housing be any different with a top loader or a TKO?

Other than the improved protection you would get from an after market bell housing over an alloy one I don't see a problem.

"Back in the day" when flywheels were MUCH more likely to fail, the new scatter shield's and steel bell housing were really needed. Today a flywheel/clutch failure is very rare. OK, you can take the "never can be to safe" position, or not, just sayin'...

Anyone on here had a flywheel or clutch disintegration in the last few years? Any other car forum guys? The one or two examples I've seen of failures that were posted (with pics) were pretty radical setups with a questionable flywheel/clutch setup already. Like an 800 horse power monster at 7000 plus rpm running a stock or old flywheel which was questionable for street use, let alone for racing.

Sure, I run a steel bell housing myself, it came with the car. I also run a Hays after market flywheel. If I was building a car, I would consider an alloy stock bell housing. Avoids that whole alignment issue thing,,,

[jhv48]

I'm inclined to agree with the above. Something out of whack with the bell housing.

However, can someone explain the following:

1. Why does the trans shift smoothly after a brief cool down but hard when warmed up?
2. Why does reverse NOT grind when carefully engaged?
3. Why does it go easily into first gear if the car is just barely rolling forward?

These symptoms seem to be related to several failures, not just the pilot bushing.

In my mind, if the pilot bushing is dragging on the input shaft, reverse should always grind, and the forward gears should always be difficult to engage. And, rolling forward should have no effect on shifting quality.

What am I missing here?

[ERA Chas]

Originally Posted by jhv48

What am I missing here?

Everything. You've asked for help and four guys on here agreed that the solution of the problem is in checking the bellhousing index and checking the input shaft length against the crank.

Stop speculating and just pull it down and you'll find the problem.

[jhv48]

Hope you're right. Don't want to do this a fourth time.

Trying to make sure there isn't a second problem that should be addressed while the trans is out.

[ekrupa2]

Jim - I am by no means a mechanic, and I only posted as I almost have the same set up us you. I speculate this is a heat issue...rather than a problem with the trans. That clutch slave line is very close to the headers and I tend to notice a change in shifting manners when sitting in stop and go traffic. But I stress nowhere to the extremes you have mentioned. I do know when I adjust my slave (via shims), I can change the adjustment only 1/32 of an inch to induce a grind when going from forward to reverse...and now know by feel where the sweet spot is. When in stop and go traffic, first gear can chatter a bit if my clutch let out is not perfect when there is no air movement cooling things down. This is not the case during non stop and go driving. I did switch to hi-temp fluid, and also installed a heat shield above the brake/clutch line prior to my motor drop. Good luck and I do hope you find the cause of your issue.

[elmariachi]

Originally Posted by ekrupa2

Jim - I am by no means a mechanic, and I only posted as I almost have the same set up us you. I speculate this is a heat issue...rather than a problem with the trans.

Part of it is a heat issue. The vibration/grinding is definitely due to a worn pilot bushing or the pilot shaft pressing against the crank. The hard-to-shift issue may be exacerbated by that as well but I believe heat in the clutch fluid is a primary factor in the clutch fading and not releasing quickly when the pedal is pushed.

[jhv48]

I thought heat might be a culprit at first so I made some heat shields and covered them with reflective heat tape and shielded the clutch lines in the engine compartment. I then replaced my hydraulic fluid with high temp Wilwood fluid. No change.

Car is heading back to the installer for it's third trans-ectomy in a year. Will let you know what they find this time. Will probably be a couple of weeks.