Tremec TKX 5-Speed Conversion

[CoronetDarter]

Didn't have the time or the foresight to take many pictures of the TIR measurements.
Picked 6:00 as the random starting point, set the dial to 0.00", and after some monkeying around, got 3 consecutive 360° repeatable sweeps back to 0. It's a bad camera angle, but the top of the plunger is not touching the bell.
Didn't get a pic of the high spot, but it's at 2:00, .082". Rotated the plunger 180° and recorded 0.00".

 

[Kern Dog]

This is a screen shot of a Youtube video made by the company the Tremec kit came from.

You all know the phrase..."A picture is worth a thousand words" ?
Well, a video takes that concept a lot further. I had an eye opening moment while watching that video.

To recap, I mentioned first reading about measuring runout in a Mopar Action magazine where Rick Ehrenberg said "Spend the 20 minutes on this and get it right".
It pissed me off because it took me several hours to do this. 20 minutes? What the hell, man?
Watching this video, a couple of simple moves they did suddenly made total sense and it made me see how it is possible to do this with precision in far less time than before.
First, they aimed to find a zero point, then the point which was furthest away, the highest number.
We did that. The number was .081 or .082. THEN they RE-ZEROED the gauge at that highest point.
Now, that new zero point is the direction that the bell has to move to.
Yeah. THAT alone made my eyes perk up. It is so simple but makes sense.
In the case of this car, the zero point was still at 6:00 but the high number is at what was it....12:00 or 2:00? Regardless, THAT will be the new zero. THAT is where the bell has to shift toward to close that number.
Secondly, they installed their dowels with the offsets aimed to where they need to move the bell.
Again, so simple, I'm pissed that I didn't think of it. With my car, I think I did that but can't be sure.
The SST guys didn't test the runout at 4 points, 12 points or anything like that. They tested it at 2 points.....the highest number and lowest. Simple.
I feel like a kid with a new toy....I want to test what I've just learned.

 

[coloradodave]

 

[CoronetDarter]

Autos need to be pretty close too...
But I do like the test you have in mind...
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It could be but the painter would have to drink a few Kamikazes before picking up the gun..

I'm now sure where you plan to measure but I'm talking about the back face of the bellhousing where the trans mounts... Like this...
View attachment 1538142

OK, got it now. Thanks.

To measure runout of the flywheel you would reposition the dial indicator so it is mounted to the block with the stem touching the clutch face of the flywheel then rotate the engine to see if the flywheel runs true or has runout.... It shouldn't..

View attachment 1538149

This is a good measurement to know, regardless of the BH runout. But, if the base of the indicator is placed in the center of the flywheel on top of the pilot bushing, would flywheel runout affect the BH register measurement?

 

[hunt2elk]

Didn't have the time or the foresight to take many pictures of the TIR measurements.
Picked 6:00 as the random starting point, set the dial to 0.00", and after some monkeying around, got 3 consecutive 360° repeatable sweeps back to 0. It's a bad camera angle, but the top of the plunger is not touching the bell.
Didn't get a pic of the high spot, but it's at 2:00, .082". Rotated the plunger 180° and recorded 0.00".

View attachment 1538151

View attachment 1538152

That's quite bad imo. I've never had one anywhere near that far off.

 

[CoronetDarter]

The SST guys didn't test the runout at 4 points, 12 points or anything like that. They tested it at 2 points.....the highest number and lowest. Simple.
I feel like a kid with a new toy....I want to test what I've just learned.

We pretty much followed the video. We measured the .082" at about 2:00. We didn't zero out the indicator. But we rotated the crank 180° and came back to 0.00" . Had we set the high point to 0.00, the 180° mark would have read -.082" and we'd still be off .041"

 

[CoronetDarter]

That's the one. Did it in 9 minutes.

 

[coloradodave]

Rich, What did you end up with? You're going to love your 5 speed...

 

[HawkRod]

On the subject of tools, Greg fabb'd a handy flywheel dowel on a moments notice. Took an extra flywheel bolt from his stash, ground down the head, cut a groove in the top for a screwdriver to back it out once the flywheel was in. Much easier to start the bolts without having to hold up the flywheel.

View attachment 1538147

Nice little dowel to help with installation! I've made similar dowels to help install the transmission on the bellhousing. I used long bolts and did the same as Greg. Then, the transmission can slip on the bolts to keep it aligned. It has helped a lot with my 23 spline 833, but I struggled more with my 18 spline. It just seems to be a b**ch to align compared to the 23. Not sure why

 

[Kern Dog]

I put the word out to a few local friends and got some help.
One guy had 2 big block bell housings. One is a steel Lakewood scattershield but the other is cast iron....From MY 75 Power Wagon! I sold the guy the 4 speed switchover stuff a few years ago.

This is what the truck looked like just after I got it and is actually sort of rare.

It had some unusual paint color and is the last of the 440 4 speed trucks built. Like a dummy, I converted it to a 727 and regret doing it.
Anyway...I have the bell from the this truck and the Lakewood. On Friday I'm borrowing one more from another guy.
Having three additional BHs will allow us to test fit and measure them for runout too.
My bonehead logic tells me that IF all of them show the runout to be in the same general amount and direction, the Bell in the SST kit is NOT to blame.
If these other three all show a variance in the runout, that may mean the SST BH is the problem.

 

[CoronetDarter]

Rich, What did you end up with? You're going to love your 5 speed...

View attachment 1538631

View attachment 1538632

Hey Dave,
We're at .041". I'm really looking forward to getting this on the road once we get past this hurdle.

 

[CoronetDarter]

This afternoon we took another look at the engine and bellhousing. During the week, Greg called around to his Mopar buddies in the area and was able to borrow two bells that we could use for comparison against the SST. One was a Lakewood scatter shield that wouldn't fit without taking out the headers, so it was set aside. The second was a stock Mopar cast iron piece for a car.
First, I removed the SST bell and flywheel to get a closer look at the engine mounting flange. Turns out it deserved a closer look. There was over spray from when the engine was rebuilt, and that came off quickly with a wire brush. But with the paint gone, a few imperfections showed up.
The most obvious was a tiny metal booger on the bottom of the flange. Something dented the flange from the side of the block and pushed up some of the metal.
You can see it at the tip of the screwdriver. There was also a lot of paint buildup.

It was prominent, put a dent in the aluminum bell flange when it was tightened down.

I used a flat file to run it down, then crocus cloth to smooth the surface.

Second, there was a hairline cut in the flange at about 2:00, and two minor ones underneath. Magnified it looked like a machined cut, not a crack. The cut was wide enough and deep enough to catch a fingernail. There was a miniscule ridge where the metal had been pushed up around the cut. We debated whether a cut could throw off the runout.

Regardless, I filed it down and smoothed it with the crocus cloth.

 

[CoronetDarter]

Feeling like the block surface was now prepped, we reinstalled the SST flywheel and bell and re-ran the runout procedure. Remember back to post 161, the original measurement was .082" and 0.00", resulting in a .041" TIR.
This time the measurements got closer to spec, but the runout kept the same pattern in that the high point was near 12:30 and the low point was near 6:30.
This time the high spot was +.003 (coincidentally, it was right next to the random starting point at 12:00). I zeroed the indicator and Greg rotated the crank 180°; the measurement was -.048" for TIR of .024".
So, wouldn't a .021" offset dowel put the bell within the .005" spec?

We tried a few other data points just to check the circumference. Ideally, each 180° set of points should equal around .051". We didn't measure exactly with a straightedge so the numbers are off a bit:
.045 + .0005 = .0455
.024 + .032 = .056
.012 + .042 = .054

 

[Kern Dog]

The discovery of the small burrs on the mounting surface of the block was a surprise. I checked 4 other blocks in the shop and none of them had any defects like that. I checked a 318, a 340 and 2 440s.
One of those 440s has a crank in it and could serve as a test engine if we need to compare the bellhousing runout on another engine. More information can be better or it can just confuse matters. I don't know which scenario is most likely in this case.

One thing that I have wondered that may or may not have any importance....
Do the dowels provide a measure of "shear" between the bell and the block?
In other words, without the dowels in place, is it possible that the bell could shift or rotate even if the bolts are tight and secure?
I would think so. I noticed that during a test fit, even with the new dowels there was some small amount of "slop" between the dowels and the holes in the bell.
There is some small clearance between the shanks of the mounting bolts and the holes in the bell.
It seems that in a block with no dowels, the bell could move around a little, maybe a lot.
I only ask this because I wonder if a bell could be tapped into spec with no dowels in place, would it stay there with the bolts tight.

 

[CoronetDarter]

Next we installed the cast iron bell. By this time, we're getting pretty good at swapping bells and setting up the indicator. Greg torqued down the backwards bolts at the bottom while I installed the two bolts towards the top. Greg also fabb'd a bellhousing dowel, which makes a world of difference when trying to line up a cast iron bell.
We're now experienced enough that we're able to produce a 0.00", 360° sweep the first time.
So, this is where it got really interesting. I was not believing the measurements so after the initial hi/lo sweep, we re-ran the sweep twice more, and at 90° intervals. The Mopar bell was almost perfectly concentric!
The random starting point was 6:00; zeroed out the gauge. Greg did a full 360° sweep and the gauge never reached a positive number until 6:00 when it returned to 0.00. At 12:00 the measurement was -.008, for a TIR of .004". We measured at 3:00 and 9:00 and the TIR was .003!

So what did we learn? First, thoroughly prep the engine block mating flange before installing the bell.
It still seems the SST bell is out of round, although it looks like it can be brought into spec with .021" dowels. Even so, I don't like being on the hairy edge of spec tolerance.
I would take the Mopar cast iron bell in a NY second, but it's a loaner, not compatible with the Tremec, and weighs twice as much as the aluminum.
Tomorrow morning we're going to reinstall the SST bell and remeasure, if nothing else than for my piece of mind that the bell and crank can be brought into spec alignment.
Are we on the right track?

 

[watermelon]

nice work all. skimmed through the thread.

fun fun fun.

right now i’m feeling like going from a 727 to a TKO 5-speed was an easier project for myself than replacing a leaking driver side freeze plug (located under motor mount).

don’t get distracted. will keep watching your progress!




watermelon

 

[1 Wild R/T]

nice work all. skimmed through the thread.

fun fun fun.

right now i’m feeling like going from a 727 to a TKO 5-speed was an easier project for myself than replacing a leaking driver side freeze plug (located under motor mount).

don’t get distracted. will keep watching your progress!




watermelon

Why do freeze plugs bother people so much? Get in, fix them & life goes on... I've done hundreds of them... Not a big deal....

 

[ckessel]

On that thread I posted from the other forum, what you ran into as far as small imperfections, was one of many contributing factors to the clutch chatter problem. The divot may seem small but think of that as the pivot point for an arm. When you get to the outer portion of the arm, it's vastly magnified. Mating surfaces need to be free of coatings, divots, burrs etc. Hope its smoother sailing once the bh is done.

 

[coloradodave]

Rich,
I'm not understanding the method. First, as had been said, I don't see how paint or a ding on the engine flange would affect runout. Yes, the ding should have been addressed, as you did. I can't help wonder after dealing with the problem so many times if something is being missed from SSTs video above. I do this all the time. Maybe re-watching it and writing down each step would help. Note at minute 3:20 where he finds the most positive point and then remarks that as the zero point. Also, are you using factory dowels partially inserted to do these measurements? They should fit the bellhousing holes tighter than the RobbMC ones to get your initial offset requirement. Good luck, my friend...

 

[Kern Dog]

Rich,
I'm not understanding the method. First, as had been said, I don't see how paint or a ding on the engine flange would affect runout.

I agree to a point. When I rebuilt my engine last year, I painted it with single stage catalyzed enamel. The back of the block got 2 thick coats....

I did end up pulling the offset dowels to clean them up and recheck the runout.

Maybe because the paint was sort of even, this didn't affect my runout? When I rechecked it here, it checked fine.

Yes, the ding should have been addressed, as you did.

It made sense to dress the ding down smooth. From there, all surfaces are even.

Also, are you using factory dowels partially inserted to do these measurements? They should fit the bellhousing holes tighter than the RobbMC ones to get your initial offset requirement. Good luck, my friend...

It made sense to start with what the engine already had in it. I don't know if they were original or replacements knocked in by some machine shop.

We tested an iron bell from a car engine and it came in almost perfect....with these factory dowels in place.
I did find that the offset dowels that Rich bought from Robb MC do have a little bit of wiggle room in the holes in the bell housing, as if the bell holes are a couple thousandths bigger than the holes in the block that the dowels fit into. It is because of this that I've wondered if the part of the dowel that the bell rides on has the full effect of their rated size.
In other words, given the slight "slop", would a .021 dowel only move the bell .018 or so?

In 2021 I bought this dial indicator kit...

It is a bit clumsy and bulky.

My first effort in measuring runout was fraught with numerous rookie mistakes. I should have marked the bell with exact marks 180 degrees opposed. The bulky and clumsy rods of this arrangement didn't allow me to aim the dial gauge near the center or where I could watch the face of it through the range. The center rod that extended from the magnetic base stuck past the bell housing hole so I couldn't put the gauge there. I made it work but it was far from ideal.
Today, I cut the rod that the arrow points to. The gauge now puts the needle closer to the center which should result in a better result with less chance of errors.
Rich has a different setup, one that I wish that I'd known about before I bought mine.