Optimal Pinion Angle...EXACTLY how do i make this adjustment...???
i spent quite a bit of time on the phone today with Mr. Kiesler and he was very helpful...
today i got her up in the air...rear tires on blocks and jack stands under the frame near the front...
according to Mr. Kiesler they have "never" had a vibration after one of thier own installs due to pinion angle...
he advised me to get the tail of the trany as high as possible without touching the tunnel...about 1/8 inch clearance...
we did that with two nice fat flat washers under each mount bolt...
another problem was that for some reason the tail of my trany was about 3/8 inch closer to the drivers side then the pass side causing a drastic misalighnment of the drivesahft from side to side...
i knotched out the slots in the trany mount a little and pulled the tail over more to the center...
i also had the shifter on "backwards" so it would hit the console when pulling it left in the gate to go to 1st gear...kind of a pain to remove and reinstall from under the car but we did it while the tail was dropped down...
we would have had it on right but we didnt know because the instructions were so vauge concerning it...
it simply said something to the effect of..."bolt the shifter to the linkage"...etc...
i think that the instructions nead some tweaking....like have some pictures or even drawings...
i think its a great kit but there is not one illustration in the instructions...just written words...in my opinion, illustrations, even rough drawings are a HUGE help when tackling a job such as this...
Mr. Kiesler was a big help and he also said that he will be checking this thread and offering some insight soon...
anyway...the bottom line is that about 90% of my vibration is gone...
at least now its drivable without worrying about something flying apart! LOL
i think tho that i will be looking more into the pinion angle and then i think i will have it...
tonight on my way home i bought a magnetic angle finder and i may tackle it tomorrow eve...
when i do i will be reporting the results etc here...of course :)
Gray also let me know today that they were modifying the warranty language to extend the time for those people undergoing restoration. I had asked about situations were the tranny may not be installed/tested for a while. Current language gives you 90 days from date of shipping. Thanks Gray.
:cheers:
ok...please do not laugh at or insult my terrible drawing... :crazy:
i alreadt know how bad it is!
anyway, this is facing forward in the car...and as you can see, the shifter is on the left...
hope this helps...
EDIT...
hhhmmm...this is wierd...my pic isnt showing up...
ill work on this...sorry
[Modified by SIGNGUY, 10:15 PM 12/22/2003]






i screwed up big time but i have no vibration...
i measured angle at the trany and got -5*...
seeing the 5* to the left of the zero mark, i guess i got confused and when i went to the rear end and measured zero degrees i thought i had to make it go to the right of the zero to be equal and opposite...WRONG!
anyway...i shimmed the rear DOWN instead of up and got about 2*...
i paid too much attention to the guage and didnt think about the up vs down (equal and opposite) angles...
i guess i was tired after a long day at work...
anyway...i didnt realize until i got home tonight (thanx to norvalwilhelm) that thats backwards from what i was supposed to do!
what bothers me is that on my test ride tonight it rode very smooth...
hhhmmm???
ok...so now i dont know what to do...
ive got 5* at the trany with it pointing down and ive got about 2* at the rear end with it pointing down instead of up where it should be...
but i have almost no vibration at all...
i would like to have it "correct" and it wasnt really that hard to do (i had a 4 post lift)...
but to be honest with you i dont really know how to raise the rear end...
tonight i also replaced the rubber donut bushing with a new one and the bottom piece of the old one was about 3/8" thick and the new one was about 1" thick...
so just by replacing the bushing, i pointed my rear end down instead of up...
so that being said, i was not only better off with the old bushing but even it was at zero which means that i would have to reduce it even more!
and how the heck do you do that!?!
to gain much at all, i would have to completly remove the bottom part of the bushing and even that would not give me 5*...???
if i put my old bushing back in...im back where i started...vibration...
what i have now is not correct "by the book" but my car runs smooth...
is it dangerous the way it is?
now im really stumped and dont know what to do...???
[Modified by SIGNGUY, 1:14 AM 12/24/2003]
The rearend in case would only need to be +3/4.
Your rearend needs to be raised so refresh my memory. To raise the pinion I would have thought the shims would get smaller not larger. It was last year that I did this so I forget.
You need bigger shims to raise the rearend???
Also most universals do not like over 3 degrees of angle so 5 is really pushing it.
I would never have thought the rear of the transmission would hang down that much.
You are still a few degrees out plus still putting the universals through an extreme angle. Something doesn't sound right.
Still glad to hear the vibration is still reduced.
at least it looked as tho it may when i looked at it...
The rearend in relation to the transmission is fixed. Changing the spring should have absolutely no bearing on it's relationship.
The angle will not change with a change in springs.
the rear end is (WAS) at zero degrees (level)
what am i missing here? right when i thought i understood this i realize that i am more confused than ever... :rolleyes:
The Best of Corvette for Corvette Enthusiasts
Anyway with the car sitting as level as possible take a reading off the back of the transmission and if it still reads 5 degrees that is what you are stuck with or shim up the back of the transmission between the tranny mount and the crossmember to decrease this amount.
Do the same for the rearend, a clean if possible pinion yoke and start I believe but not sure decreasing the shims to push the nose of the pinion up.
You are trying to get the angles equal but opposite but also less then 3 degrees.
The fact that you already decreased the vibration shows that you are headed in the right direction.
When I installed my Tremec I reworked the hole around the shifter and a little tunnel work around the output yoke so the transmission would be pushed up really high, I then did fiberglass work in these area to strengthen the area.
It made for a pretty flat installation and little shimming on the pinion.
Good Luck Signguy and I am glad to see you are doing something about this.
at any rate, your previous post there seems rong from the way I read it anyway....
if you raise the tranny tailshaft...you would increase any driveshaft angle...the things are in there kinda high to start with, let alone any higher, I have yoke rubbing troubles, and ebrake cable rubbing needed cured....
raising the pinion would help the tranny yoke, but at expense of pinion yoke....
thing is, I never saw any shims under either one on my car, just the urethane or rubber pads in case of the pinion....and just the normal tranny mount on either the Muncie or the 700r4, which I had to modify the mounting shoe to lower it, and move bolt holes to rear....I just made it work, no more clearance available on that tranny mount back to the support shoe...
I ran it all through the speeds/gears yesterday trying to get critical about vibration...must have been a good day....seemed quite normal....smooth...
GENE
my car (frame) sits level at reat on the ground (or 4 post lift)
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"you should use a yoke in the transmission that has been cleaned up for burrs and paint and place it in the back of the transmission"
actually...i placed it on the rear of the tail of the trany (up and down...
beside the yoke...i didnt remove the driveshaft...
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"shim up the back of the transmission between the tranny mount and the crossmember to decrease this amount"
i already did that as much as possible...
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"Do the same for the rearend, a clean if possible pinion yoke"
actually...i couldnt really get at the rear yoke with the driveshaft still in the car...i measured the angle from the back of the diff housing where the back "cover" bolts to the diff...which should be at a 90* angle from the driveshaft...correct?
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"decreasing the shims to push the nose of the pinion up"
well...actually there are no shims there...just the bottom piece of the rubber bushing...which i had a replacment for...
and as i said above...the old one was "flatened out" to about 3/8" vs the new one which is about 1" thick...which apparently worsens that angle...
should i remove it and put the old one back in, i will be back where i started and the vibration is worse there than where it is now... :rolleyes:
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"The fact that you already decreased the vibration shows that you are headed in the right direction"
well actually i am way off although i have almost no vibration...
my trany tail points down and so does my diff at the front...
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"I reworked the hole around the shifter and a little tunnel work around the output yoke so the transmission would be pushed up really high"
well...i wish that i had done that now but i am not crazy about doing that especialy since that would mean removing the trany again :rolleyes:
althought that DOES sound like the ultimate solution...
thanx so much for helping...
It is to our advantage to install the transmission as high as possible, A slight bit of work around the hole in the floor for the shifter and a little work around the output yoke and the trasmission can be installed quite high to make for a better shot at the pinion.
I used a jack to hold the transmission as high as possible then welded in a mount on the crossmember that held it high without shims.
I will have to go back and read my and your post to see what I said wrong but it could be my typing, I tend to type quickly and not proof read afterwards. My fingers are faster then the brain some times.
By the way Gene why are you and this early and what happened to Twin Turbo? He usually chimes in on these posts.
if i put my car on jackstands from under the frame...
ala, wheels dangling...
will my diff angle stay the same?
or does the rear end have to be sitting, "squated"...compressed as in rest on the ground?
Gene this is wrong. The transmission points down to begin with. YOu get a negative reading so anything you do to raise the transmission decreases the angle so it approaches zero. Signguy has his transmission hanging down by 5 degrees, raising the transmission helps cut this angle down. The pinion read 0 so he has a problem, Part is the hang down of the transmission and part is to raise the pinion angle higher.
I never said , just jack it up is easy. Sure the yoke will begin to rub but you will find a rib right at the end of the yoke that with a little grinding yields alot more room, Take a grinder and start grinding a few of the high spots off, like this rib and it makes for alot more clearance, paint it afterwards and you will not see the grinding, I run a full 3 inch driveshaft, your stock is 2 1/4 inch and I have no rubbing problems anymore.
you freaking guys, now I have to go out in the damn garage, and even though it's been FINE since '97, I have to go check it out.....jeez....
GENE
QUESTION...
if i put my car on jackstands from under the frame...
ala, wheels dangling...
will my diff angle stay the same?
or does the rear end have to be sitting, "squated"...compressed as in rest on the ground?
Unless your frame is totally rusted and flexing the rearend stays the same regardless if there is weight or not. Sure there is a slight flexing with the rubber mounts on the rearend crossmember and the rubber on the pinion shim but it is minimal and at the amount you are out it make no difference.
Regarding taking readings without the car level think if the front of the vet was parked on a steep hill and you took reading off anything the angle of the hill would be added in with the reads. Your protactor takes reads from level,
Guys I am heading out now so see you later
Hope Stider has eaten his breakfast, he has a fast run this morning.
Guys sell the vets and get a good horse, no vibration, no pinion angles to worry about and keep in mind this is a girls hobby, not a guys so the barn is full of pretty girls in tight riding close and not afraid to get dirty. :crazy: :crazy: :lol: :lol:






Wheres that darn angle finder? :confused:
I agree with the sign guy , my Tremec install read 5 degrees when I first started with it. I then removed some tunnel portrusions and some off the top of the box and gained about .5 degees. Then lowered the rearend 1 inch in the back and about .5 inch at the pinion to balance both operating angles at 3 degees to achieve smooth operation.
I"M kinda curious< as my exhaust is hanging lo so my ***** drag the ground too< and well if i raised the suspension some, that would give me better ground clearance....interesting...give the car a rake too....gotta give this some thought...
GENE
It is better to trim around there then dropping the transmission and increasing the driveshaft angle.









