TREMEC T56 Magnum S197 Transmission

[bullitt boy]

In 4th at under 40mph you will hear the rattle I would call that "lugging" and always drop to 3rd til 40mph + and no rattle noise.

 

[AutoXRacer]

Is there something wrong with driving the car/motor between 1,500-2,000RPM?
That's where I cruise and drive most of the time while in town and highway.

 

[ZmanM3]

Is there something wrong with driving the car/motor between 1,500-2,000RPM?
That's where I cruise and drive most of the time while in town and highway.

I do the same.

 

[Hatchman]

I got the rattle as well, especially in third and fourth gear under 2000 rpm. I just try and avoid it and drive around it. Hasn't gotten any better with use.

I'm thinking the 3.55 gear is really tall with the wide ratio even with the twin screw torque. That and my rear tires are taller than stock, so it's the equivalent to a 3.46 axle ratio. It's a little tall.

 

[AutoXRacer]

I am extremely happy with my 4.10s and wide ratio T-56M XL!!!

The pull is freakin out of this world!!! But, cruise any faster than 80 MPH and your efficiency/economy goes out the door.

At 80 MPH, I was at 2,000 RPM.
I typically cruise between 60-70 MPH which falls right between 1,500 and under 2,000 RPM sweet spot.

I got to give thanks to Lito for turning it around!!! I was really unhappy with the performance of my car...now, I can't stop driving it!!

Thanks Lito!!!

 

[danzcool]

I have that issue with my TR6060. Never found a cure

Thanks for the response. It's not more than a minor annoyance, but when you know that it's nothing more than a sensor or a tune issue, it really gets at you.

...HG6283 - My cruise works with 5th and 6th. Something in your tune maybe?

Is that on a tr6060 or T56/S197 magnum?

I've got to believe that something can be done, because I doubt the GT500s have a no-cruise 5th, and it's the same PCM, just a different tune.

 

[AutoXRacer]

With my T-56M XL, I can cruise control in any gear as long as its above 40 MPH I believe. The cruise is only limited by speed and I think minimum RPM as mine shuts down if I go below 2,000 RPM...or something like that.

I think its tune related.

 

[HG6283]

Thanks for the response. It's not more than a minor annoyance, but when you know that it's nothing more than a sensor or a tune issue, it really gets at you.

I do a fair amount of long-distance travel with this car. There are times when I would have liked to use the cruise control but I was not going fast enough for 6th gear.
I've looked at the wiring diagrams, and I don't see a sensor which tells the PCM what gear I'm in. So I'm thinking it has to be a tune related issue.
A certain combination of engine RPM versus speedometer reading...???
It appears to be hit-or-miss. Not everyone has this problem. I've heard of one guy who has cruise control in all gears except Sixth. That would really suck.

 

[AutoXRacer]

It would be interesting to hear about the guy that has no cruise in 6th. What RPM is he trying to engage the cruise in?

If its below 2,000 RPM, I think thats his issue. My cruise control was shutting down if my RPMs fell below 2,000 RPM; when I was coasting down hill.

 

[BruceH]

The number of gears and ratios are part of the tune. How that affects cruise control I don't know. I do know that the factory settings allow the use of cruise from 27 to 125mph and those numbers can be adjusted.

Just a guess here but let's say the tune wasn't updated for a 6 speed or the different gear ratios in the trans. That could cause a large enough speed error that cruise would shut down.

 

[AutoXRacer]

Hey Bruce, what about RPMs?

 

[BruceH]

Hey Bruce, what about RPMs?

I don't see anything. There is a minimum torque but it's all - at operating rpms.

 

[HG6283]

It would be interesting to hear about the guy that has no cruise in 6th. What RPM is he trying to engage the cruise in?

If its below 2,000 RPM, I think thats his issue. My cruise control was shutting down if my RPMs fell below 2,000 RPM; when I was coasting down hill.

I got the story 3rd hand about no cruise in 6th, so there's no way to find out now.
In any case, I have had the problem with both 3.73 and 4.10 rear gears.

.

 

[danzcool]

The number of gears and ratios are part of the tune. How that affects cruise control I don't know. I do know that the factory settings allow the use of cruise from 27 to 125mph and those numbers can be adjusted.

Just a guess here but let's say the tune wasn't updated for a 6 speed or the different gear ratios in the trans. That could cause a large enough speed error that cruise would shut down.

As far as I know, the number of gears has not been changed from 5 to 6 in the tune, I'm going in for a tune next week, so I'll have him look for it.

 

[1950StangJump$]

The "rattle" in the 1200-1800 RPM range is the tranny - I tried a couple different clutches and they did not make much difference. One clutch/tranny combo might transmit less than another, but that is all. I drove a few different Magnums and each had different noise levels (all had it). Comes down to luck and your tolerance level.

Seems to be a common complaint with the Magnum. 4th gear is the worst, I assume because the 1:1 ratio transmits noise so much better than other gears.

I never got cruise to work in anything other than 6th. At one point, 6th didn't work either, but that was a function of the tune and was remedied by a revision.

 

[pacettr]

Ok, finally got a decent 2 hr drive in of slow, stop-n-go back roads. 1st - 4th gears from 1,400 rpms - 1,800 rpms sounds like a someone shaking a can full of rocks.. I can be accelerating easy, hard, or just maintaining speed and it's noisy as hell. Once I get into 5th or 6th it's quiet as can be.

Is this normal? ..could it be the McLeod clutch?

Yep, its normal unfortunately...

Mine does the same from 1,500-2,000 RPM. Gets worst with light weight flywheels and aluminum/carbon driveshafts. The heavier your drivetrain, the quieter.

It doesn't really get quieter in my opinion. The only thing I have recently found that quiets it down are 4.10 gears. Must be due to the drivetrain seeing less load. It was really bad/loud with my 3.55 gears. I hated it; totally avoided that RPM range.

Now with the 4.10s its still there, but doesn't seem to come up as frequently and not as loud.

I had the same noise with my TR3650 too... Got really aweful with an aluminum flywheel and aluminum driveshaft. I reverted back to stock driveshaft because it was so loud and annoying (when I had the TR3650).

I have the (stock) 3650 along with alum flywheel, RST, and alum driveshaft. I also experience this "rattle". I ASSumed it was the larger diameter shaft rattling against the trans tunnel...?

 

[BruceH]

I have the (stock) 3650 along with alum flywheel, RST, and alum driveshaft. I also experience this "rattle". I ASSumed it was the larger diameter shaft rattling against the trans tunnel...?

I had it with a 3650 and 6060. The only thing in common was a twin disk clutch. It didn't do it with the stock clutch. It's known as floater plate rattle.

 

[1950StangJump$]

I have owned or driven 3 Magnums with the Twin disks, Centerforce, and other single disks. Different flywheels, too. All made the rattle in varying degrees. The RPM in which the noise was noticeable varied some.

Thinking about this, the noise probably is the clutch (with the Twin Disk clutches making the most racket) ... I think the Magnums convey the noise greatly while other "stock" trannies hide it better. But, even with trannies produced for factory cars, a clutch change will change the harmonics and introduce noise.

The Ford engineers probably put much time into matching harmonics to ensure such noises don't exist on mass produced cars.

 

[lito]

I just ordered a custom geared Magnum, wish me luck!

 

[AutoXRacer]

I just ordered a custom geared Magnum, wish me luck!

What gears?