Overtorqued Pressure Plate Bolts Cause Grinding?

[TaurusPimpin]

I have just converted my '97 Vulcan-powered Taurus to a manual using the MTX-IV from a '93 SHO (I know, it's not a real SHO!). I got it running on Tuesday, after months of planning, and two weeks under the car. Now I'm having a lot of difficulty shifting.

From a stop, I have no problem starting in first or reverse. Once the car is moving, however, I will depress the clutch pedal and push the shifter to the desired position, as far as it will go. As I release the clutch pedal, the tranny will grind, and I will quickly press the clutch pedal again, and the tranny will engage the gear. This mostly happens in third and fourth, but I have done it in second and first while moving. At first I thought it was because I forgot how to drive a manual, but the frequency that it does this, and the fact that the shifter seems to stop make me doubt it. I can shift the car while it's not running, and feel the shifter click into gear consistently, in all gears.

The tranny is from a '93, with 15k miles on a rebuild (donor car threw a rod bearing). The shifter is the rod shifter from a '95, and the clutch is a brand new BeckArnley (has Valeo printed on the disk) for a '94 Tempo. Flywheel is also new. I put about 2.5 quarts of Valvoline ATF (non-synthetic) in before driving it. I filled it until fluid was coming out of the fill hole, so it should have plenty in there.

Hindsight being 20/20, I checked myself, and I did overtorque the pressure plate bolts to 35 ft-lbs. I was thinking that this might cause the clutch to never fully disengage, which would cause my grinding and why it would not engage until the engine speed had dropped a bit. I wanted to confirm that this screw up could be the culprit before I started dropping the subframe again. Sorry for the long post!:thankyou:

 

[techi14]

make sure the reverse assy bolt (which some use for a drain) is tight. Last time I forgot to tighten it all the way and caused problems similar to yours.

 

[SASHO91]

That is the proper tq. Btw, post some pics of your swap!!!

 

[TaurusPimpin]

I though correct torque was 24 ft-lbs?

 

[SASHO91]

It's a two step, 24-34ftlbs is the norm.

 

[TaurusPimpin]

Ahh, I wonder if I didn't bend the clutch disk or something when aligning and installing the tranny. What's a good test for full clutch disengagement?

I checked the reverse assy bolt, and it's certainly in there tight.

Here's the interior.

 

[TaurusPimpin]

All right, I did some more searching, and it looks like hard shifting can be attributed to a few things: Bad/Low fluid, Bad driver (very likely! ), clutch disengagement problems, or bad blocking rings. I'll try a fluid change this afternoon after I get out of classes, and try driving some more. I'll test for clutch disengagement while the car is still on stands too. I really hope this isn't a blocking ring issue.

 

[93rev2sev]

If it's a blocking ring issue, rev matching will allow you to shift without issue.

If it's a clutch dis-engagement issue, that griding will be present at a stop...with the clutch pressed.

 

[TaurusPimpin]

Haha, I'm afraid to try clutchless shifting by rev matching just because I'm not familiar with it yet. The only time I never have problems getting into gear is from a stop, so that would rule the clutch out, wouldn't it?

 

[Bizzy]

Did you make sure that the clutch disk was aligned properly? In other words, it's not on backwards is it? I don't know about the Tempo disk, but the SHO disks are normally stamped "To Engine" on one side.

SHO transmissions will hold 3.1 quarts of fluid. When you refill, be sure that the car is as flat as possible. If it's jacked up on one side or front end up you won't get a complete fill.

Other outside the trans things that could cause problems would be shifter alignment. Is there anything interfering with engagement when all 4 wheels are on the ground? And motor mounts. Many people experience shifting issues when they have bad/broken mounts.

Good luck with it! It looks like a cool project! I love the shifter on the floor idea.

 

[TaurusPimpin]

Oh, I did have the front end up when I refilled it; maybe I'm a little short then. I'll pull the drain plug with the car on the ground and see if I can add some more fluid. Yeah, the Tempo disc did say FW side, so I'm about 99% certain I'm good there; it also had a raised section where the damper springs are in the center, so I'm sure I would have noticed if it went in backwards, but mistakes do happen.

The cat and post-cat oxygen sensor on the the Y-pipe do come rather close to the linkage and brace, but they were not touching. I'll check this with the car on the ground as well. Motor mounts are both brand new; I replaced those and went with aluminum subframe bushings during the swap. I'll also pull the carpet back (good thing the passenger seat is still out!) and make sure I cut a big enough hole. I'm pretty sure I tested it before I put the carpet back, though.

Yeah, at first I really wasn't sure I would like how it looks, but it's grown on me. The car really wants to be driven; if I can get the shifting fixed, it will be a blast. Good Vulcan (relatively) low range torque plus low SHO gearing sounds like fun to me! It sounds a lot meaner with the SHO pipe and resonator on it too.

 

[Phoenix]

Is it me or since when you can mate a MTXIV with a Tempo MTXIII clutch? Yea ok some Tempo came with a MTXIV ,but its easier to order a SHO clutch , so it MUST be a MTXIII PP& clutch...right?

 

[TaurusPimpin]

I believe all Vulcan Tempos used the MTX IV. The clutch should be the same as the pre-upgrade 9.25" SHO clutch, I think.

 

[TaurusPimpin]

Well, I ended up having to help a friend move furniture to his sister's new apartment, so I'm not getting anything done tonight. When I check the fluid tomorrow, would it be a good idea to put in something better? Is there anything wrong with the Valvoline ATF I put in?

 

[zak]

It's a two step, 24-34ftlbs is the norm.

From this thread, its first step 12, second 24 fl lbf. For aluminum flywheels, I think that gets backed off to 22 ft lbf. Did the original poster use loctite?

Too much loctite can make the clutch hard to release (gets on facings).

zak

http://www.shoforum.com/showthread.php?t=75991

 

[TaurusPimpin]

No loctite. I was going with the Tempo instructions from the '94 Ford Service CD, since I was using that clutch and flywheel on the Vulcan, and the CD doesn't mention threadlocker .

 

[TaurusPimpin]

Well,I can't find anything interfering with the shift linkage, and with all four wheels on level ground, I pulled the drain plug, and got a trickle of fluid to come out. I can stick my pinky in and feel fluid just below the plug hole. Could overfilling cause issues? It's looking more like either a driver mod is needed, or internal problems.

 

[Bizzy]

Over filling isn't going to cause any problems. The worst thing that happens with over fill is you get some trans fluid that will blow out the vent.

You may have stated already, but with the car off and not using the clutch pedal, there are no problems shifting through the gears? If there are no problems with it off but there are problems with it on, that would lead me to believe that it's clutch related.

Things to try:

With the car off, run through all the gears from 1st thru 5th & reverse without pushing the clutch pedal down. Do the same from 5th to 1st & reverse You should be able to engage all the gears this way without any problems.

With the car running, clutch pedal down, but Not moving, run through all the gears as in the previous step. Do all the gears engage easily and without grinding?

With the car on the road, run through all the gears. Try to shift at lower RPMs. (Low but not lugging the engine when you engage the gear.) ie: 1st gear to 1k-2k rpms, 2nd gear at 2k rpms, etc. etc. all the way through 5th gear and then from 5th to 1st, again at lower rpms. Are there any problems then?

Then do the same except shifting at higher RPMs. Any difference?

Do you hear any whining sounds when engaging a gear?
Has anything been done to the trans? ie: rebuild? new parts?
Are you sure you're pushing the clutch pedal all the way down?
Is there any interference with the clutch pedal when pushing it down to the floor? In other words, are you REALLY pushing the clutch all the way in or just as far as you can make it travel given the conversion?

At this point I'm still thinking clutch or some sort of interference issue, but it I can't rule out synchro or blocking ring issues.

 

[TaurusPimpin]

I can shift through the gears with the car sitting, on and off, and it's not much of a problem, although sometimes it feels like it will stop, and I have to push a little harder to get it into gear. This is mostly in third, fourth, and sometimes reverse. I drove it around the neighborhood again today, and I found that if I run it up to about 2500 RPM, it shifts a lot better, into every gear (though I only went into fifth once; can't get that fast in the 'burbs). I still get the feeling like it stops, and then I push some more and it will go into gear.

The tranny should have 15k on a rebuild, and the car it came from was junked because of a rod bearing. I've checked the clutch pedal, and I'm getting full travel. I held it down as far as I could with my hand, and then tried to fit a finger behind it. There is clearance behind it, though not much.

 

[Bizzy]

On a complete rebuild at 15k there shouldn't be any problems, but that is totally dependant on what was replaced during the rebuild. Another factor would be how the PO drove his/her car and the condition the that the clutch/PP was in when it was installed on the junked car.

I'm pretty much out of ideas short of dropping the trans, checking the clutch/PP assembly and opening up the trans and inspecting it for damage.

Edit: You might consider swapping out the trans fluid with Mobil 1 or Royal Purple or GM Synchromesh just to see if it makes a difference.