510 angle/alignment of trans to Diff

[RoadRace]

hey - anybody ever checked the diff to driveshaft to trans angles?

do you know what they are supposed to be?

how did you confirm or check them?

 

i was trying to check with a magnetic 'tilt box' i got from Lee Valley - but there doesn't appear to be a flat spot on the diff or the trans output flange

 

any help would be super - thanks

[datzenmike]

I would guess the engine driveshaft and differential are level. The differential is fixed and unmovable.

[shlammed]

would love to know the answer too... will help me set it with my swap.

[ggzilla]

On 7/30/2025 at 7:36 AM, RoadRace said:

trying to check with a magnetic 'tilt box' i got from Lee Valley - but there doesn't appear to be a flat spot on the diff or the trans output flange

The transmission output flange is an easy place to do it. Put a large socket over the nut, then place the gauge on the socket, to get the angle reading

 

Only need to measure the transmission level because the differential is fixed in an IRS vehicle. When you swap a different engine/gearbox combo in, make sure it is installed at the same angle

 

Also, since the engine crankshaft and transmission shaft are inline, you can measure off the engine oil pan flange, block deck, or cylinder head surface

[Duncan]

On 8/27/2025 at 9:51 AM, datzenmike said:

I would guess the engine driveshaft and differential are level. The differential is fixed and unmovable.

 

If you Google "pinion angle setup", there are quite a few diagrams available that explain it pretty simply.  It is really pretty simple.   

 

 

 

[RoadRace]

i ended up using a rectangular block of aluminum, 6" x 3" x 3" and mounted it to the output flange on the trans and then on the diff.  the diff is fixed but there is still room for error, I like the pan rail idea. i'll keep that in mind to verify other dims.

Edited August 28, 2025 by RoadRace

[datzenmike]

 

Only the 521 has the nut on the main shaft at the transmission output. 

 

I wouldn't even bother checking this. Transmission and differential are solid mounted on rubber mounts. The body would have to be bent or you noticed a low vibration when driving to suspect something wrong.