1961 Cadillac Drive Train Alignment

[John Washburn]

Folks,

It is good to have Cadillac friends, but sometimes it is really hard to fix the problems they bring to you.

My buddy has a 61 convertible with a vibration in the drive shaft. The shaft, carrier bearing, transmission mounts are all new, as is the rebuilt engine. The drive shaft was tested to 3500 revolutions and did not vibrate (at the shop). Our buddies at A-1 Transmission helped us understand that it not likely to be a tranny problem.

Oh, buy the way, he wants to drive back to Canada next Friday. This is his second try. First time the 61 blew two rods.

Now the intersting part for 61/62 the shop manual shows that one must use a J-8905 Kent Moore Kit to align the two part drive shaft both vertically and horizonatlly. This is a real Rub Goldberg tool. In 63 things change and this complicated adjustement is no longer listed.

My question is: Is there an easier way to adjust the drive shafts, the carrier bearing to remove the vibration (which occurs under power) without this special tool? We now plan to move the adjustment left to right to see if this is the culprit, but wonder if anyone (who is not now at the Grand Natioal) might have experience with. Or does anyone have this tool, for sale or loan?

Porter, Im sure you have had this problem in your extensive years of Cadillac experience... Help us out...

Anyway, all parts are new, so I am somewhat confident (yes, when the problem is located it will be fun to see how good the old guesses are?) that it is in the alignment.

Help!!

John Washburn
CLC #1067
Elizabeth, Colorado

P.S. the 31 LaSalle project is getting more interesing by the minute.....

[Porter 21919]

John,

The oldest cars I have ever owned were 1965 vintage.

Ed Mobley & Bruce Reynolds are the 1960 guys, they have or are currently dealing with the same problem.

Bruce will most likely jump in here, Ill email Ed and tell him you need his 2 cents.

Porter

[Ed Mobley]

Hi John,

Ive been looking for the J-8905 tool for the better part of the year.  Ive even been calling up Cadillac dealerships to see if they might have the the tool sitting around.  Ive even contacted a guy who sells a lot of old Kent Moore tools and he doesnt have one.

Without the tool, one would just be guessing what the correct angles are.  The Motors manual from that era gives the angles for other GM two piece drive shafts but says the cadillac shaft has to be adjusted by the dealer because a special tool is required.

Question: Are the vibrations at high speed or low speed?  If they are at high speed, you most likely have a driveshaft balance problem.  If they are at low speed, you have a geometry (driveshaft angles) problem and need this tool.

In my case, I get a slight shudder at around 10mph when going up hill.  It got better when I replaced my transmission mount and shimmed the mount up with a couple of washers.  But my process has been trial and error.  At high speeds I have no vibration at all.

Regards,

Ed

[Bruce Reynolds # 18992]

Gday John,

I apologise for not being handy to answer your question, but I was out for the day, enjoying looking at the shops in Sydney.   Boy, those LCD and Plasma Displays are dear.

Anyhow, back to the problem at hand.

I have been chasing the vibration in my 60 CDV, for many years and tearing my hair out doing it.   Now, what I had was a bad shudder between 5 and 15 mph, and a whining vibration at cruising speed.   Funny thing, there is no sign of any shuddering whilst taking off in reverse, either slowly, or fangin it.

Well, a good balance and straightening solved the cruising speed problem, and the shudder although still evident, is liveable.   I replaced the top balljoint, stuck in various shims under the centre bearing mount and replaced all universals, and checked all the locating bushes.  

In the end, I shimmed the centre bearing 1/8 and moved the mount 1/8 to the right side, by elongating the holes in the chassis with the deft use of a file.   That has made the car driveable, but I intend to replace all the bushes in the hope that I can completely resolve it.

Bruce,
The Tassie Devil(le),
60 CDV

[Johan Boltendal # 158]

Not that I have any exp. with 60s Cads but have you tried the following. Try it above a greasing or inspection pit!!

The reverse no shutter at all gave me the idea.

Have someone move the car back and forth, with one foot on the brake, be in the pit yourself, to see what happens under load.

Look how the drive train moves and the difference in this movements back and forth, also look at the movement of the rear axle and engine. This might lead the way to a solution.

Any way this will find the position of all movable parts,in which there is no shutter at all.

We have done this and it has solved some mighty hard to find problems, we were not able to locate in stationary condition. Perhaps this helps.

Johan

[Doug Houston]

I think  that Johan has a good thought. It might even be good to check for a loose engine mount, either at the front of the block or even the one on the transmission tail housing.

I had to check your location, and what follows will be useless to you! This is about the driveshaft. I had a 64 convertible; a daily driver. This has a 2 piece drive shaft, with one of the joints being a back-to-back Cardan joint. This is one type of constant velocity universal joint. Its one that cant be replaced by normal procedures. If you dont believe it, try it like I did!

In Detroit, theres a place named: Joint, Clutch and Gear. They are the masters in that business. Seeing how I had messed up the job, I sent it to Joint Cluth and they replaced the CV joint, balanced the thing, and you never saw a smoother drive line!

If you were closer to Detroit, you could send it to Joint Clutch, of course. I wish I knew of another place nearer you that I could recommend, but I dont. I suppose that if push came to shove, the shaft could be crated and shipped to Detroit. Since there is such a driveline vibration, and since its true character isnt firmly understood, not much driving could tear the transmission right out of the chassis!

[BOB DIEDERICH]

JOHN, I JUST REINSTALLED A 2 PIECE DRIVE SHAFT IN A 62 ELDO AND THE BOLT HOLES WERE NOT SLOTTED FOR LEFT AND RIGHT ADJUSTMENT. THE ONLY ADJUSTMENT WAS WITH A FORKED TYPE SHIM, THERE FORE ALL THE ADJUSTMENT SEEMS TO BE UP AND DOWN. MAYBE ADD OR REMOVE A SHIM. I DIDNT FIND ANY BODY IN MY AREA THE HAD THE KENT MOORE TOOL. IF YOU PUT THE SAME SHIMS BACK THAT YOU REMOVED IT SHOULD STILL BE ALIGNED.
GOOD LUCK BOB D CLC 16618

[BOB DIEDERICH]

JOHN, CHECK THE REAR TRANSMISSION MOUNT. THE REPLACEMENT MOUNTS REQUIRE A SHIM BETWEEN THE MOUNT AND THE FRAME. IAM TRYING TO REMEMBER WHERE THE SHIM WENT BUT YOU CAN ONLY PUT IT IN ONE WAY.
 JUST MY NICKELS WORTH BOB D CLC 16618

[George UK]

The best way to chech the drive chain.
  Jack the car up safely.    
 Partly apply the parking brake, enough to create load. then run the car at the speeds the vibration occurs. Someone underneath the car will see the problem.
MAKE SURE THE CAR IS SAFELY SUPPORTED.

[Jim Smith]

In 1959 I purchased a new 1959 Oldsmobile 88 two door hardtop model from an Olds (and Cadillac as I remember) dealer located in San Jose, Ca. After driving it out the dealership and accelerating to the to the first stoplight located a block away, a serious vibration problem on acceleration was obvious. After about three trips back to the dealer with no results except excuses I managed to sneak back into the dealership shop where the mechanic had my car up on the hoist and was able to get some straight info.  He showed me the tool used to measure the proper angular alignment between the two drive shaft sections by raising or lowering the carrier bearing. In my case all the shimms had been removed and the bearing was still much too high.  He tried then grinding off the bearing base as much as possible but still could not get the angle needed but it did help some.  His opinion was that the frame had been damaged or sprung someway during manufacture or delivery. As he said, good luck getting a dealer or GM to replace a frame.  In those days there were no lemon type laws but a  surplus of willing buyers. About a year later I sold the car at a discount to a buyer who said he didnt mind the vibration.  Sorry, this doesnt help to solve your problem but is a remote possibility of cause of the problem.   Jim

[Paul Flykt #18899]

John
Street rodders have dealt with this vibration since they started swapping drivelines. I am familiar with the first part of my reply the second is what makes sense to me as a place start with out the Kent Moore tool.

If the engine and transmission mounts are in good shape check the angle of the output shaft on the transmission as compared to the second u-joint and pinion shaft on the third member. These should all be the same angle, in other words they should be parallel. A magnetic protractor from Sears will give the readings you need to check this. In order to fine tune the angles it may be necessary to raise the transmission or carrier bearing with shims. You should only have to do one or the other not both. These angles should be within 1 degree of each other. This should solve any vertical alignment issues, horizontal or left to right alignment would be another story but here again everything must be parallel.

Here is the part I have not had to do but where I would start. I would start out by making sure the rear end is square with frame and the engine and transmission are also. I believe in 62 they are all centered in the frame if not it should only be the rear end that isnt. About the only thing that could be wrong here should be a bent frame or bad bushings in the trailing arms. Bushing are an easy so fix lets hope for that. Assuming everything is centered and square the only adjustment would be at the carrier bearing to bring the front half of the driveshaft into alignment. This you should be able to check with either a straight edge or string line from the center of the pinion shaft to the center of the output shaft on the transmission.

If you need a better explanation I know I have an article regarding driveshaft angles from a hot rod mag somewhere in my files. just email a phone # and I will fax it.

Paul
pflykt@barbarossa.com

[Porter 21919]

http://www.classictruckshop.com/driveline.asp TARGET=_blank>http://www.classictruckshop.com/driveline.asp

[Paul Flykt #18899]

Thanks Porter

I was just going do an internet search rather search thru a large box of stuff, some filed and some just stuffed for future filing. I checked the forum and you saved me the search.

Ill bet the Kent Moore tool is just an inclinometer of sorts.

Maybe the people interested in modified cars can impart a little useful knowledge after all.

Paul

[Michael Stamps 19507]

Those that push the limits tend to find the problems way before the normal user ever would.  Weak rocker design in the 472/500s never would have been corrected without those that push the engines way above the rpms a normal Cadillac driver would.  Want to get more performance and gas mileage out of one of those engines but look stock?  Talk to Lynn ... I swear he could get a 100 point engine past the CLC judges making 50percent more power.

Stampie

[Paul Flykt]

Here is another link regarding drive line angles that references a Spicer tool for checking these angles. The price of happiness is a little steep at $300.00. Ill stick with my Sears model, identical to the one in Porters link.

http://www.drivetrain.com/driveline_angle_problem.html TARGET=_blank>http://www.drivetrain.com/driveline_angle_problem.html

[Porter 21919]

Stampie has a stock 60 Flat top, the 70 SDV will have a few more cubes bored into the block and a free flow exhaust.

My 66 CDV is stock sans paint and vinyl top, my free 67 CDV RR will be whatever it will be.

http://www.modifiedcadillac.org/ TARGET=_blank>http://www.modifiedcadillac.org/

We have photos too, come on down ! (join the mod squad)

Porter

[Ed Mobley]

The Kent Moore J8905 is not an inclinometer - I wish it was that simple.  Ive got the documentation for the tool if anybody is interested.  It is quite an intricate tool.

Regarding the link to driveline angles that Porter and others pointed out, it is impossible to achieve them on this type of Cadillac two piece drive shaft.  For example, try to jack up the transmission or lower the drive shaft carrier bearing low enough to get the first u-joint angle to 1 degree or less.  The transmission will hit the body of the car with 4 degrees to go.  Better yet, try to get the middle u-joint and pinion u-joint at complementary angles as specified for two piece drive shafts.  You cant do it on this car due to interferance from the frame.

For that reason, Cadillac came up with the Kent Moore J8905 tool.  I just wish they would have specified the angles so one could use an inclinometer instead.

Regards,

Ed

[Ed Mobley]

Heres my driveshaft geometry details from a prior post:

All,

To continue my driveline saga:

Here are the measurements from my driveline on my 1960 Caddy Coupe. They raised more questions than provided answers:

Tranny - 6.75 degrees up
Front shaft - 2.25 degrees up
Rear shaft - 3.5 degrees up
Pinion - 1 degrees down

So, the working angles of the front and rear u-joints are 4.5 degrees so they cancel each other out. But the working angle of the middle joint is 1.25 degrees.

The result of these angles is contrary to what I read in the the following post regarding two piece drive shafts:

http://www.vibratesoftware.com/html_help/html/diagnosis/Propshaft/Propshaft_Angles.htm TARGET=_blank>http://www.vibratesoftware.com/html_help/html/diagnosis/Propshaft/Propshaft_Angles.htm

Can be the middle u-joint be the odd joint? Or does the odd joint have to be the one by the transmission? Even if the middle joint can be the odd joint, 1.25 degrees is excessive according to what I read. But Ive also heard they can be as much as 1.5 degrees.

Another thing I noticed is the yokes on the rear shaft are out of phase by 7.5 degrees. Ive read that some two-piece shafts are designed to have some out of phase yokes but I dont know if they mean 90 degrees out of phase or just a few degrees out of phase. As such, I dont know if this is factory or not. Im thinking the shaft may have twisted since the piece on the end has a friction fit with the rubber damper and all. According to the following post, yokes should not be out of phase by more than 2 degrees:

https://www.fleet.ford.com/truckbbas/non-html/Q14.pdf

This piece from Ford leads me to believe that the middle joint can be the odd joint as shown by some of their illustrations. In other words, the front piece of the driveline does not have to be an extension of the transmission shaft as per the first post.

I tried moving the rear of my transmission up, but there is not enough room to make the front part of the shaft come out straight. Shimming the middle support would only increase the working angles of the front and middle u-joint.

[Ed Mobley]

NM

[Paul Flykt # 18899]

Ed
I am curious where you read your angles on the transmission etc. Did you use the pan and the driveshafts themselves. Ill crawl under my 57 and see if there are any similarities.
I have a very slight shudder at speed that Ive blamed on my tires, it could be in the drive line.
Paul