After aligning the bellhousing per Lakewood procedure, I went back and reread both Keisler & Lakewood procedures and they seem to be in conflict. I talked to both tech reps and confirmed the conflict. Keisler states that for measuring radial alignment, the max allowable indicator reading is 0.005" which means the max allowable misalignment
is 0.0025". Lakewood states that the max allowable misalignment is 0.005" which means the max allowable indicator reading is 0.010". Both these statements have been confirmed by the respective tech reps. Does anyone know for sure which is the true maximum indicator reading? You might ask, why don't I just adjust to the lower 0.0025" figure and be safe. Well, I've been chasing the misalignment for a while, currently have 0.007" dowels in and I don't want to keep chasing this unless it's necessary. Current max indicator reading is 0.0045" to the right, which is O.K. per Lakewood but not O.K. per Keisler.

 

Excellent question.
I have a vibration that may be due to this issue.

 

Bell housing manufacturers do not determine the max allowable misaligment measurements, the manufacturer of the transmission does. In the case of a Tremec TKO, the maximum allowable TOTAL runout is .005 (or .0025 from the center of the register hole). The method by which we and our customers measure runout has been used on over 4000 transmission installations with accurate results. While there are other methods for determining runout, we find that our method is the simplest and most accurate way for our customers to determine how the bell housing lines up.Hope this clears up any confusion.

Richard
Tech Support
Keisler Engineering

 

This clears it up in my mind, with the additional explanation of the discrepancy. Seems pretty simple. The Keisler/Tremec spec is tighter than the Lakewood spec. I'll be punching out the old dowels and puching in new dowels.

 

They make dowels that have concentric sides that can be adjusted and give you zero runout.
Bernie

 

If the tranny states maximum .005 runout this means that you can be plus or minus .005. That is you can run up to .005 off centerline.
That also means that if you zero the dial gage on one side the other side can read .010 and you are still .005 off centerline.

 

Dowels don't come in every thousands of an inch. I could look it up but I am lazy. I would be suprised if they cam in anything more then .010 increments.
It is not that easy removing the old dowels and then getting the new ones aligned is another problem.

 

This is the point of the question. Your comment is the same as the Lakewood spec which is double the Keisler spec. In your example, zeroed on one side, the Keisler spec allows a max of only a 0.005" reading on the other side. The Keisler spec relates to the reading. That means a max of only 0.0025" runout.

 

I'm not sure that this is true! If you rotate a shaft that is true about a bore that is offset by .0025 it will strike an arc that is +/-.0025 i.e .005 runout.

 

I have the tremec spec sheet that came with my tremec and they clearly state .005 runout maximum. You answered you own question when you said That means a max of only .0025 runout.
I would go with the .010 maximum allowed on the dial gage.

 

I interpreted it as meaning a .0025" spec and adjusted my bell accordingly. Dowel's come in .007" increments.

 

You're right, except that the Tremec sheet doesn't define runout. The Keisler alignment procedure defines runout as the dial indicator reading. Half the dial indicator reading is defined as misalignment. Looks like the definitions are critical in this case.

 

Tremec states runout at .005", what that means I have no idea, .005" on each side of centerline or what ?

 

From Motorheads sheet the centerline of the crank and the centerline of the transmission must be the same. You can not deviate from the centerline by more then .005 runout. That means you can be on either side of centerline but not more then .005.
What if you were on the low side say minus .003 on one side and plus .003 on the other side. Are you saying the runout is .006 or the total or are we actually still within .005 of the centerline???? Never having deviated from the centerline by more then .003????

 

Yes, if you have a dial indicator reading -0.003" on one side and +0.003" on the other side, you have a total reading of 0.006" and you exceed the spec. (best to zero one side for clarity which you can do mathematically: left side reading=-0.003", right side reading=+0.003". Add 0.003" to each side which doesn't change the relationship. Then left reading=-0.003+0.003=0, right reading=0.003+0.003=0.006" which is the total reading). If you draw yourself a picture of two circles with centerlines offset by 0.003" you'll see that one side of the offset circle is 0.003" closer to the true center (call this minus 0.003") and the opposite side is 0.003" further away from the true center (call this plus 0.003"). When you do a dial indicator measurement from the flywheel, the indicator rotates around the true (flywheel) center. If it's zeroed on one side, it will read 0.006" on the opposite side i.e. the reading is twice the offset of the centers. What kiesler and Tremec are apparently saying is that the maximum allowable dial indicator reading is is 0.005" or that the maximum offset of the centerlines of the flywheel and transmission shaft is 0.0025".

 

It is pretty clear what Keisler has stated. Not so clear what Tremec is saying and it is clear what Lakewood is saying, that is if you dial indicator reads .010" you have .005" runout or offcenter as they put it

 

Gentleman:
Please stop, every one is going to drive the other crazy
I deal with this question every day all day. I will try to clarify. You start with the indicator at the 12:00 position and zero it out. Next, rotate the engine to the 3:00, 6:00 and 9:00 positions, writing down the measurement at each respective position. Let's say at 3:00 your get a .004 reading, at 6:00 you get a .009 and at 9:00 you get -.010. That tells us that your TOTAL runout on the 12:00 and 6:00 axis is .009 and the the TOTAL runout at the 3:00 and 9:00 axis is .014. If you take the largest runout reading (.014) and divide by 2, that tells you you need .007 offset dowel pins to correct the .014 measurement.Getting the offset pins dialed in the right position is another story. In my example, you would "clock" the .007 pins towards 5:00 and fine tune it as necessary. This will move the register hole down and to the right (looking at it from the trannys perspective) and put the TOTAL runout to within the .005 tolerance as specified by Tremec for the TKO. I cannot speak for the Lakewood instructions but I can tell you the tolerances on the Muncie were not as tight (more like .010). Now keep in mind, because the Muncie tolerances were not as tight, it was acceptable to use a brass bushing in the end of the crank. Because TKO tolerances are much tighter, ALL "kit" makers supply the needle roller pilot bearing. Of all of the questions I receive throughout any given day, measuring runout is by far the most "complicated" procedure of the entire installation process. That is why I usually ask our customers to get their measurements and call me and I will help them figure it out. I am not an engineer nor a math wizard (more like the kid in the back of the math class daydreaming of surfing ) but I am an avid car nut and have a pretty solid background and understanding in this area.
I will be more than glad to help anyone out if they ask.

Richard
Tech Support
Keisler Engineering

 

Richard is actually right about runout. He must have had at least one eye open in math class.
Skip the Lakewood offset dowels and use the Moroso ones as they are much more user friendly. Moroso dowels are slotted WRT the offset. Put a center punch mark near the slot side of the dowel with positive offset. Install these marks pointing in the same direction or you will never get that heavy SB bell housing on over the dowels. With the bell housing bolts loose you can rotate the dowels in a parallel mode with a brake adjusting tool or 90 deg. screw driver while monitoring runout.

 

What is the relationship of pilot bearing type to tight tolerances. Is it O.K. to use a bronze pilot bearing with the Tremec? I'm a little worried about reliability. What life can you expect from the roller bearing? Does itr compare to say, 200,000-300,000 miles for a bronze bearing.

 

Yes definitly use Moroso, Lakewoods are a PITA.