SOT 3 link install on my 69 coupe

[rwcstang 187]

got the week off to tackle this, so far its been a crazy experience. Im looking forward to getting this girl back on the road!

 

[rwcstang 187]

Hey Guys, hoping you can help me out with something, as I'm a little stuck. my lack of knowledge of pinion angles is none existent and im trying to understand it correctly. Before I start, Im running the following: poly motor mounts and stock rubber trans tko mount from MDL. after reading about how pinion angle works on different sites, the summary is they are supposed to be 3" degrees or less and suppose to cancel each other out under acceleration, however, I think I may get my pinion angle wrong.

 

with the MDL TKO conversion kit w/ their Trans Mount, before adjustment, we measured the trans angle at - 4.5 Degrees down, however, I didn't check the angle of the pinion with the stock axle/leafs, ugh I wish had.

 

we shimmed the MDL trans mount, and the best we got was +3.5 degrees up and transmission was already hitting the top tunnel/shifter hole, also per SOT instructions, we started the 3rd link at 3 degrees up as a baseline and I lowered it 2 degrees down to 1 degree, this was to compensate from the pinion moving up when accelerating, assuming I did this wrong, would someone educate me? should I have done - 3.5 down instead?

 

OR

 

should I have left the TKO Trans mount as is (4.5 degrees down and raised the 3rd pinion angle slightly higher to match the transmission angle, when under acceleration they would cancel each other out or do I have it wrong?

 

still got a lot to learn here, so excuse the ignorance and overthinking.

 

https://www.motortrend.com/how-to/pinion-angle-change?slide=2

[Casgar 19]

I'm pretty much a novice too, but from what I understand it's the relative angles between the transmission and the pinion, and their centerlines that is of interest.  The angles relative to the car/ground is more a concequence of trying to keep the driveshaft angles correct.

Also, I think the 3-link would raise the pinion less under acceleration compared to leaf springs.

[det0326 168]

Ideal would be 1 degree down on transmission tail shaft and 1 degree up on pinion yoke. Since 3.5 up is all u can get on the TKO without tunnel modification then u need the yoke up 3.5 degrees. On stock leaf springs u would want pinion up 2.5 allowing 1 degree wrap up on take off but on the 3 link probably not necessary.

[RPM 1,107]

On my triangulated 4 bar rear I put the trans and pinion at the same angles. No issues after 6 years. 

[rwcstang 187]

On 2/20/2023 at 9:05 AM, RPM said:

On my triangulated 4 bar rear I put the trans and pinion at the same angles. No issues after 6 years. 

Thanks, I spoke with Shaun and he recommended the same thing, I mentioned to him that my 3rd member sits slightly higher than the shimmed transmission mount, he still said to put the angles the same, so trans down, adjust the 3link pinion up, so Im going to take a few shims away and let it sit at 4 degrees down and raise the pinion angle to 3.5-4 and see if the clunking while shifting/acceleration improves, it will most likely look like image 3 but reversed. 

[rwcstang 187]

On 2/20/2023 at 8:53 AM, det0326 said:

Ideal would be 1 degree down on transmission tail shaft and 1 degree up on pinion yoke. Since 3.5 up is all u can get on the TKO without tunnel modification then u need the yoke up 3.5 degrees. On stock leaf springs u would want pinion up 2.5 allowing 1 degree wrap up on take off but on the 3 link probably not necessary.

yeah, Im going to drop it some to 4 degrees and adjust the 3link to match the trans, originally with the MDL mount it sat at 4.5, at 3.5 degrees the TKO is rubbing against the trans tunnel and making a squeaking/metal rubbing sound and driving me nuts as it comes and goes

I do have a TKX to install but later on, and since the TKX and TKO600 are the same and one is smaller, I can probably go back down to 3.5-3 degrees with out touching the tunnel, they use the same mounting hardware. but going to try to adjust with the TKO as I need to keep testing this suspension and brake in the new 3rd member. 

excuse the drawing but assuming its going to look like this after I adjust it, the other option is to raise the car and adjust the coilovers and have the 3rd link/pinion get closer in balance with the transmission. 

does that make sense? 

[det0326 168]

2 hours ago, rwcstang said:

yeah, Im going to drop it some to 4 degrees and adjust the 3link to match the trans, originally with the MDL mount it sat at 4.5, at 3.5 degrees the TKO is rubbing against the trans tunnel and making a squeaking/metal rubbing sound and driving me nuts as it comes and goes

I do have a TKX to install but later on, and since the TKX and TKO600 are the same and one is smaller, I can probably go back down to 3.5-3 degrees with out touching the tunnel, they use the same mounting hardware. but going to try to adjust with the TKO as I need to keep testing this suspension and brake in the new 3rd member. 

excuse the drawing but assuming its going to look like this after I adjust it, the other option is to raise the car and adjust the coilovers and have the 3rd link/pinion get closer in balance with the transmission. 

does that make sense? 

That should work fine.