Black Jack: Fixing torque steer

02 281 GT said:

I have so many watched threads because of seemingly random useful information like this.

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Along those lines, this is an old explanation and table of recommendations from Wolfe Racecraft:



I would add that knowledge to the article I posted earlier when I talked about setting pinion and engine angles at parallel under normal operation.

02 281 GT said:

I know it's probably too late to mention this, but after looking pretty in-depth into the differences between long tube headers for 1994-1995 and Fox cars, there are only two differences: the EGR provision on the passenger side for 1994-1995 (passenger header is dimensionally the same as the Fox cars) and the 7-o'clock clutch fork position on the 1994-1995. The 1994-1995 headers and mid pipes are routed differently (above the clutch fork rather than below). These are the ONLY differences I could find and confirm. With that in mind, you could probably have solved the clearance issue with a set of 1994-1995 long tubes.

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That's excellent info. I suspected something like that, but I didn't want to pay for a set of headers. Maybe I'll find a set in the future I can pick up affordably. Or, if the pinched primary ever becomes an issue, then I'll look to upgrade.

jrichker said:

The NSS or Neutral Safety SWitch does not have anything to do with starting the car in gear. It is used to prevent you from doing the Key On Engine Running computer diagnostic tests.

If it does not work, you will get a 67 code.

Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests. You can generally ignore this code, since it has no effect on engine performance.

The computer wants to make sure the A/C is off due to the added load on the engine for the engine running tests. It also checks to see that the transmission is in Neutral and the clutch depressed (T5, T56, Tremec 3550 & TKO)). This prevents the car from being driven while the computer is in test mode. Key On Engine Running test mode takes the throttle control away from the driver for several tests. This could prove hazardous if the computer was jumpered into test mode and then driven.

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Thanks, Jrichker! Still helping me out. Much appreciated, bud. Needed help figuring out what it was and what to do with the extra wire. I'll just wrap in and tie it up, for now. I'll consider looping it in the future, or just jumper it when I need to run diagnostics.

More or less finished T56 install. The yoke is significantly further out than it should be. Looking for 3/4 - 1". It's ~1.8" out. With 1.5-1.7" of spline engagement I decided to go ahead and take it for a cautious spin.

It went ok. 1st 4 gears are fine. At 50-55, it started vibrating. Tried 6th, which made things worse. Decided to take it easy & come home. Vibrations maybe be the pinion angle being completely out of whack, as I maximized the spacers on the trans. Might take a look at that tomorrow.

I'll get an 11/16" spacer Mon-Tues and install it. Then, I'll feel more comfortable doing a more rigorous test drive.

Despite the fact that the pigtail connected right up from the OSS to the old VSS connector, Michael Bell was right, it seems. Cruise control does not work. It accelerates when pushing the button, but does not maintain speed.

My biggest hope it to get rid of the vibration between the pinion angle & driveshaft spacer. If that happens, I'll be very confident in working through the rest.

Finished up the T56, tonight.

Driveshaft length is a bit short: I received the Steeda 11/16" spacer. It should have been 0.6875", but measured 0.669". On a straight edge, it looked like the yoke extended out beyond the output shaft housing by ~1 3/16 - 1 1/4". Ideally, I wanted .75" - 1", but according to the other rules of thumb, the amount of yoke-to-output-shaft spline engagement will be fine. I'll keep my eye out for a 44.5" driveshaft, which, without the spacer, would be just about perfect. But, I suspect, this will be good enough. While, I have a 44.5" FMS driveshaft on my garage floor, the vibrations it caused eliminates it from ever going back into a car.

*edit:* I'm editing this for my own future reference. After a lot of subsequent work on the D/S to reduce vibrations, I realized that I'd been measuring wrong. I used the point on the yoke that begins to expand away from a 'flat' cylinder as the baseline for measurement. I should have bottomed out the yoke in the transmission, because the yoke will not fully go into the trans. It was difficult to get a perfect measurement with the tools I had available to me at the time, but I believe the distance I'd been measuring as a baseline was 1/2 - 5/8" with the yoke bottomed out in the trans. Therefore, given the measurements above, it would put the actual yoke extension at between minimum 0.5625" (9/16") - 0.75" maximum. This may be worth addressing later with more precision as .5625" may present some risk of impact to the output shaft. This also means that a 44.5" driveshaft would not work. Another option to consider may be a better yoke. I believe the yoke on my buddy's D/S went all the way in, despite being perceivable the same length. In any case, for the time being, I'm choosing to take the risk.

Vibration very minor and/or eliminated:
I checked the pinion and engine-trans angles. The pinion was nose up ~2*, while the engine-trans was nose up ~2.3*. I left it alone. On the test drive, it no longer had the vibration that the old driveshaft caused. The D/S spacer probably helped in this department too, by moving the forward U-joint closer to the output shaft and reducing any wobbling that the previous limited spline engagement length may have caused. While there is still a minor tremor above 75 mph, it feels like it's the rear tire and not the drive line. More driving will help me figure that out. I suspect it may be my old Nittos. I plan to swap the winters back on at some point to test that theory. It's possible the new-to-me-but-used driveshaft or its yokes may be to blame, but my gut tells me that they aren't.

Driving Impressions & Gear comparison:
I could tell a MASSIVE difference with that 2.66 1st gear. I gave it a sporty-ish launch, and it bogged like it never has with the older 3.35 1st gear. I revved to 3k and came out of the clutch aggressively, was not at WOT and it bogged down pretty far. With the 3.35 1st in the T5, anything above ~1,500 RPM would have easily spun the tires. The T5's 1st gear yielded ~26% more torque than the T56.

It didn't like 6th below ~50 mph (~1,300 RPM), where the engine has some pulsation.

For comparison's sake, 1st gear will run just about 10mph more (44 vs. 34 mph) to the limiter. I'm honestly not a fan of how much harder it's going to be to launch the car, now, but I am a fan of how much more useable 1st will be in normal street driving. In 6th gear at 80, I'm taching 2,150 RPM on the 275/40/17 Nittos, whereas with the T5, I was right at 2,900 RPM. That's a HUGE difference to NVH, and I'm sure MPG, that will make things nicer on a longer trip!

Up next :
- On Friday, I'm looking forward to seeing the impact to the fuel economy in the car.
- The MM caster/camber plates came in. I'm going to get 'em in, and have the caster set so that hopefully the steering will return to center on its own.
- I intend to roll the driver's fender because on sporty-ish cornering, I can hear what I believe is some part of the tire repetitively hitting the fender lip.
- Concerned about rear-end whine, a bit.
- Car's ready for nitrous, now... This is a long-term aspiration. Hopefully some progress here in the Summer.

FastDriver said:

Vibration resolved... mostly

Well, guys, I got the driveshaft back from the shop. The fella I worked with there, named Michael, said that while it was balanced, run-out was about .030" on each end. He used some heating/cooling technique to straighten it out. Said when it was done, he had it to about .008". He said they liked to see .005" but that was the best he could do.

I reinstalled it, this morning. I'm excited to say, the improvement in the vibration is a night and day difference! Now, before I lead you on about it, I can still feel a very slight pulsing at 75. It's something I can live with, and I will not buy a new D/S over it. However, it's also something I would sense even if I drove the car for the first time, and it's unfortunately at a speed I spend a lot of time on the highways at. That said, by 83 mph, I can't feel it anymore unless I'm trying to feel it by holding the shifter and focusing on it. By 90, it's gone, even there. Under 70-ish, there's also nothing. I'm so relieved to have finally found and almost entirely resolved it. It was maddening. Now, I can turn my attention to other things.

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Here ya go, guys. The D/S was perfectly balanced, but it wasn't 'true'. It had a runout of about .008" which continued to cause a noticeable vibration and after more driving after the above post, I'd say it was most perceptible from about 63-80 mph. The vibration was no longer overwhelming as it once had been, but it still was annoying. I also don't think prolonged use would be good on the main bearing in the trans or the pinion bearing in the diff. So, I plan on scrapping it.

edit: And now (29MAY23), I think the driveshaft was no longer a problem, at this point. Turned out that the rear carrier bearings/pinion bearings were at least part of the driveshaft issues that I had. The original driveshaft was definitely contributing massively when it was out by over .030", but at .008, it was probably no longer a leading contributor, though it may have been the cause of wear for the rear-diff bearings.

F@#$ Black Jack:
Despite my genuine excitement to finally get back on the road after the trans install, the car cranked over but wouldn't start, this morning... Smells strongly of fuel. Hooked up my spark tester and spark looks fine. It's totally out of the blue to me, and I have no earthly idea what changed since I drove it into the garage and shut it off that could possibly have affected the start. Maybe I flooded it?

Since the last test drive I've:
- swapped the O2 sensors from each bank to the other
- hooked up the reverse lockout to my shifter switch, which also controls the line lock (disconnected it and it still didn't start)
- tightened an upper control arm lock nut that came loose

Starting to hate this car, and can't take too much more s@#$ from it. What I need is to be able to reliably drive it for a few months, without messing with it. I want to solve this no-start issue, install MM Caster/Camber plates & align it, and then leave it the hell alone and drive it & hopefully enjoy it for a long time before I mess with it again.

Rgr. I will do my due diligence before I buy anything. Honestly, if this D/S doesn't cause any issues, I may just leave it alone.

Starting and Driveability problems:
It does seem to get spark & unlike my problem with the MSD box before, the spark does not die out in 15+ seconds of cranking it over. So, I think the spark is good. I tested it both at the wire from the coil and also on the #5 wire.

Concerned it was flooded, when I got home from work, I tried starting again & got nothing. So, I unplugged the fuel pump to be sure it was 'choked' while cranking it over, and I got a little bump. I guess when it leaned out a bit, it cranked. Plugged the fuel pump back in and cranked. It started! I revved to 3k for 20-30 seconds. Then decided to let it come down. It died. Couldn't start it again. I tried several more cycles of unplugging the fuel pump, cranking, unplugging, and cranking again, and it failed to crank like it had before. I also checked to make sure that it was getting good fuel pressure. It may be a set a bit light at 36 psi, but that shouldn't prevent it starting.

I started working down the no start checklist, but honestly, I find it hard very hard to follow. It's not particularly detailed in some spots where I don't know how to follow it, and I don't have a 'noid light'. Screw it! So, I just swapped my known-good distributor back in to check the PIP & TFI all in one go. Maybe... possibly... it may have helped, but it's still having significant problems. I couldn't get it to start so that I could set timing until I had a buddy come over and crank it. I turned the distributor while he cranked and we got it started. He revved and held it long enough for me to set the timing. I replaced the spout connector, hopped in, had a hard time starting, but it finally did. So, I drove it down my rural road and back about 2 miles total. It did fine for a bit, and I was careful to keep the RPM up to prevent stalling. Then, I tried 3/4+ throttle and the car fell on its face. At low load, it did fine. So, I brought it home.

I've got several ideas, but the first one I want to try is to pull the + Battery cable and hopefully clear whatever tuning tables the backwards O2 sensors likely F'ed up. I have a hard time believing that this is it, because I know that the car isn't supposed to change the fuel by more than 12% in either direction, and further I doubt that it can significantly change the initial starting conditions by enough to prevent cranking. But what do you guys think? Maybe fuel pressure? Could the reversed O2 sensors have caused the computer to create this condition?