Has anyone done the Magnum XL swap and regretted it?

[cgornowich]

I think you may be off in your tolerance. If the smallest offset dowel is .007, then anything needing less than that is probably within tolerance.

I agree with your logic, but I'm wondering if the smallest offset (of 0.007") would be of any benefit. Being on the edge of acceptable tolerances is rarely best, even if it is "good enough". Seems to me if I offset the bellhousing 0.014 (which is what the 0.007" would do) I would be about 0.00425 in the opposite direction. So instead of an offset of 0.00975 toward the "7:00 o'clock position" I would be 0.00425 to the "1:00 o'clock position". I know it's splitting hairs, but now that the transmission is out and this should be my last clutch for a long time, it seems a small effort for a small gain. But it can't hurt.... This seems better to me.

Thoughts?

 

[TMSBOSS]

Do you meet the tolerance requirements from the manufacturer now?
Can you call the manufacturer and ask their experts?
This site has smart folks who have done just about everything. But, there is no harm an asking the “Pros”.

 

[xr7]

I would try the .007, closest to zero is best, couple of bearings and one syncro will benefit. The other piece is how accurate is that plate?

 

[cgornowich]

It's a QuickTime product made for this specific purpose, aligning this QuickTime bellhousing, so it should be pretty accurate. My dial gauge is accurate to =/- 0.001", so the plate should be at least that accurate. I ordered the 0.007 offset dowels, should be here late this week. I'll report back to the group with the readings once I get them in and the bellhousing mounted.

 

[EF1]

Now, the fun part. I wanted to check the alignment of the bellhousing. So I re-installed the bellhousing and bolted on the indexing plate (Summit Racing has 'em). That rod sticking out of the hole is a magnetic base for dial gauge.View attachment 85323

I installed the gauge and spun the engine (by hand) until the gauge read the lowest number. I reset the ring so this was "0".
View attachment 85324
Then I spun (OK "rotated") the engine (OK, the crankshaft) and marked off the measurements in roughly 45 degree increments. The goal is the locate the highest reading. It's 0.00975". Since we take this measurement and divide it in half, and I think the tolerance is 0.005", it seems my engine is bellhousing is barely within Tremec's "standard" spec. Some say this spec is less for engine reving over 7,000 rpm, but I have not seen this on Tremec's literature. So I dunno.

The offset dowels come in 0.007, 0.014, and 0.021. So even the smallest would actually only gain me 0.001 closer to spec.

So, now I'm wondering what to do.....

Any opinions?

The spec is .005". You take the largest number after setting the zero and divide by 2 and if you have less than .005" you are within spec. If you try the offset dowel pins to get it closer to zero you need to move it away from the high number toward the lower number. After doing this you need to determine a new zero and start over. A properly indexed bell housing does nothing for the clutch, but it reduces side load on the transmission input shaft which prolongs input shaft bearing life. If you are not indexed within spec and the front bearing gets chewed up, Tremec will not honor the warranty. It sounds like you didn't have proper preload on the slave cylinder which caused it to over extend and leak fluid onto the cluthc/flywheel which led to your failure. Good luck on this go around.

 

[cgornowich]

The spec is .005". You take the largest number after setting the zero and divide by 2 and if you have less than .005" you are within spec. If you try the offset dowel pins to get it closer to zero you need to move it away from the high number toward the lower number. After doing this you need to determine a new zero and start over.

Do you meet the tolerance requirements from the manufacturer now?

Here's a quote from Tremec's installation literature, I pulled this off their website:

MEASUREMENT QUICK REFERENCE
STANDARD AUTOMOTIVE BELLHOUSING ALIGNMENT SPECIFICATIONS: Concentric: +/-.005” or .010” TIR Parallel: +/-.001” or .002” TIR
HI-PERFORMANCE 7,500+ RPM BELLHOUSING ALIGNMENT SPECIFICATIONS: Concentric: +/-.0025” or .005” TIR Parallel: +/-.0005” or .001” TIR
FLYWHEEL RUNOUT .001” TO .005” MAX (LESS IS ALWAYS BETTER)

I'm going to install the 0.007 dowel pins as Eric directed and measure the system again. If it's closer to zero, great. If not I can always revert back to the current offset with the old dowels.

 

[cgornowich]

I have search the entire internet (OK, I googled a little) to locate the RM-140 Offset Dowels (0.007 for a modular Ford motor) and can't find them anywhere. Summit, Jegs, Holley, and ModernDriveline all say this dowel set is "not available" and Summit lists the "should ship" as August 10th.

Wow, I remember when transmission came with a few different sizes for free. Does anyone know where I locate a set? Post here or PM me. Thanks

 

[EF1]

I have search the entire internet (OK, I googled a little) to locate the RM-140 Offset Dowels (0.007 for a modular Ford motor) and can't find them anywhere. Summit, Jegs, Holley, and ModernDriveline all say this dowel set is "not available" and Summit lists the "should ship" as August 10th.

Wow, I remember when transmission came with a few different sizes for free. Does anyone know where I locate a set? Post here or PM me. Thanks

Try Silver Sport Transmissions. They are a Tremec Elite Distributor located in Rockford Tennessee. Call them, they have more in stock than their website shows. I bought my Magnum XL from Modern Driveline last year because they were the first one that could ship a close ration swap kit. Silver Sport saved me on a steel clutch alignment tool and dowel pins. They are local to me. I called and ran over their and they went into the shop and got me what I needed.

 

[cgornowich]

Try Silver Sport Transmissions. They are a Tremec Elite Distributor located in Rockford Tennessee. Call them, they have more in stock than their website shows. I bought my Magnum XL from Modern Driveline last year because they were the first one that could ship a close ration swap kit. Silver Sport saved me on a steel clutch alignment tool and dowel pins. They are local to me. I called and ran over their and they went into the shop and got me what I needed.

Hey Eric, I'll try them in the morning. Thanks,

 

[EF1]

Hey Eric, I'll try them in the morning. Thanks,

Make sure your magnetic indictor on the dial indicator is solid. I was getting out of spec measurements on mine. I bought offset pins and then was getting erratic measurements. I ended up pulling a couple of flywheel bolts to make sure the base was solid and started getting consistent measurements. I ended up having to buy another set of factory alignment pins since I chewed mine up on removal. I was in spec with the factory pins and was able to finish up the install. I will look and see what offsets I have. If they are .007 I will let you know.

 

[cgornowich]

Make sure your magnetic indictor on the dial indicator is solid. I was getting out of spec measurements on mine. I bought offset pins and then was getting erratic measurements. I ended up pulling a couple of flywheel bolts to make sure the base was solid and started getting consistent measurements. I ended up having to buy another set of factory alignment pins since I chewed mine up on removal. I was in spec with the factory pins and was able to finish up the install. I will look and see what offsets I have. If they are .007 I will let you know.

You were right on the money: I called SILVER SPORT TRANSMISSION this morning and they had the 0.007 offset dowels in stock and are overnighting me a set for a reasonable price. So there's no need to dig through your spares, it's handled. I had to pull two flywheel bolts to create a solid location for my magnetic base as well. I figured since there were 6 left fastening the flywheel to the crank, it would be fine. I took the measurements twice, with a "resecuring of the magnetic base" before the second test and the measurements were identical, so I'm fairly confident that they're accurate. Or, as accurate as the gauge can be, +/_ 0.001.

Thanks for your help!

 

[EF1]

You were right on the money: I called SILVER SPORT TRANSMISSION this morning and they had the 0.007 offset dowels in stock and are overnighting me a set for a reasonable price. So there's no need to dig through your spares, it's handled. I had to pull two flywheel bolts to create a solid location for my magnetic base as well. I figured since there were 6 left fastening the flywheel to the crank, it would be fine. I took the measurements twice, with a "resecuring of the magnetic base" before the second test and the measurements were identical, so I'm fairly confident that they're accurate. Or, as accurate as the gauge can be, +/_ 0.001.

Thanks for your help!

Happy to help. There are only like 10 Tremec Elite distributors in the county and i happen to be sitting within an hour of two of them. I wish I could have gotten my Magnum XL from Silver Sport, but at the time they couldn't give me an eta, only put me on the list. I ended up finding one at Modern Driveline out in Idaho. It took a week and a half to get here by truck, but I got it. Silver Sport helped me on a couple things during the install. They were very helpful and it was great that they are only 1/2 hour away. They do not have a retail store, but i was able to call ahead and pick up in the front office.

 

[cgornowich]

Happy to help. There are only like 10 Tremec Elite distributors in the county and i happen to be sitting within an hour of two of them. I wish I could have gotten my Magnum XL from Silver Sport, but at the time they couldn't give me an eta, only put me on the list. I ended up finding one at Modern Driveline out in Idaho. It took a week and a half to get here by truck, but I got it. Silver Sport helped me on a couple things during the install. They were very helpful and it was great that they are only 1/2 hour away. They do not have a retail store, but i was able to call ahead and pick up in the front office.

Had some time to work on the Mustang last night, and the results were not what I was expecting. Below are three pictures, the first is the initial measurement with the stock dowels in place. The second and third are the .007 offset dowels, the second are offset toward 1 o'clock and the last is point toward 7 o'clock (because I thought my math was wrong). I'm at a loss why the second one did not reduce the run out as predicted. I know these numbers may be slightly exaggerated, because my dial is not measuring a completely square radius. But I thought it would be better than the initial runout. Hmmmm, I need to think about this one some more...

 

[EF1]

Some of it may be the gauge and base. When your dealing with .001" 's of an inch breathing on it can affect readings. My guess is the weight of the gauge on the mount is flexing slightly as it is turning causing some of the variance. Also, the middle picture looks like it was clocked towards 7o'clock not 1o'clock since it added close to .007 to the original measurements. I am not sure what happened on the third one. Did you find a new zero on each of the new scenarios? The zero will not stay in the same place after installing the offset pins.

 

[cgornowich]

Some of it may be the gauge and base. When your dealing with .001" 's of an inch breathing on it can affect readings. My guess is the weight of the gauge on the mount is flexing slightly as it is turning causing some of the variance. Also, the middle picture looks like it was clocked towards 7o'clock not 1o'clock since it added close to .007 to the original measurements. I am not sure what happened on the third one. Did you find a new zero on each of the new scenarios? The zero will not stay in the same place after installing the offset pins.

Maybe my explanation of how the offset dowels were "facing" is not clear, but the difference between the second and third pictures are the dowels facing 180 degrees different, or exactly opposite. I did find a new zero for each time remeasured. All numbers are positive, there are no negative numbers shown. The magnetic base seems to be firmly mounted each time. I guess my best course of action would be to revert back to the stock dowels and measure it again, as that's the only time I measure once. It seems I might be in the same boat as you, Eric, where the orginal standard dowels net the best measurement.

 

[EF1]

Maybe my explanation of how the offset dowels were "facing" is not clear, but the difference between the second and third pictures are the dowels facing 180 degrees different, or exactly opposite. I did find a new zero for each time remeasured. All numbers are positive, there are no negative numbers shown. The magnetic base seems to be firmly mounted each time. I guess my best course of action would be to revert back to the stock dowels and measure it again, as that's the only time I measure once. It seems I might be in the same boat as you, Eric, where the orginal standard dowels net the best measurement.

I understand that the 2nd and 3rd were 180 degrees from each other. It just looks like they were moving opposite of what you said. The 2nd one did not have a zero marked, so I was just making sure you were re-zeroing after each turn of the offset pins. The 3rd one looks like it was moving the right way from the bottom left quarter. Make sure the gauge needle is riding on the middle of the plate and re-measure a couple of times to make sure the measurements are consistent. Then I would do the same thing using factory round pins to see what nets the "best" readings. Hopefully your factory pins came out easily and you didn't chew them up with vice grips like I did.

 

[EF1]

Looking at the first picture, with the dial indicator, the lower readings were obtained when the dial was at the bottom of the arc and higher readings when it was at the top using down. This leads me to believe there may be a little flex in the mount.

 

[EF1]

One more thought, if the rod on the magnetic mount is not perfectly parallel to the crank centerline it will introduce some variation in the measurements.

 

[cgornowich]

Looking at the first picture, with the dial indicator, the lower readings were obtained when the dial was at the bottom of the arc and higher readings when it was at the top using down. This leads me to believe there may be a little flex in the mount.

You might be right. I'll take a few more readings to ensure they are consistent and see where I end up. My original dowels came out fairly easily, though I used vice grips as well and they have slight "tooth marks". I think I can use a small hand file and take care of them. The saga continues...

 

[cgornowich]

So I finally think I got it, there was some slight marks on the bellhousing that I sanded down and now we're reading .008 max run out, I'm happy with that and moving forward. The flywheel is mounted and I'm assembling the clutch pack. This is my first clutch with organic plates (the earlier ones have been ceramic), what do I clean organic plates with? I'm used to using acetone on everything......