Project: Recycle

[Alan's Classic]

This is all out of my realm of experience, but I'm trying to pay attention and learn something.

[SCOTI]

I'm heading over to my buddy N2billets house this week to take some measurements on a stock height truck just to get an idea of where the numbers are @ stockish height for comparison.

[MattA]

Good luck finding a stock height anything around that place.

[67cheby]

Originally Posted by MattA

Good luck finding a stock height anything around that place.

that was funny....

[N2TRUX]

Originally Posted by MattA

Good luck finding a stock height anything around that place.

Oh, you might be surprised at whats around that shop.

[SCOTI]

Originally Posted by N2TRUX

Oh, you might be surprised at whats around that shop.

Yep, that's why I stopped by..... At this time, there happens to be a stock height truck in his driveway. The trans output is angled down 3° min, both d.shafts are angled down 2.X°, & the pinion is pointing up (couldn't get a solid measurement on that w/o removing the d.shafts).

[67cheby]

with cool "CUSTOM" paint

[SCOTI]

Originally Posted by 67cheby

with cool "CUSTOM" paint

Amazing what was considered 'custom'....

[67cheby]

well at least it's not a hot pink heartbeat stripe !!

[n2billet]

Originally Posted by N2TRUX

Oh, you might be surprised at whats around that shop.

That's just hurtful......besides you don't know what I have in my dad's shop now..

[N2TRUX]

Originally Posted by n2billet

That's just hurtful......besides you don't know what I have in my dad's shop now..

Yeah, I'm not on the A list these days, so nothing would surprise me.

[SCOTI]

Originally Posted by SCOTI

I got a few hours today & played around w/the angles..... again. What I wound up w/was 2.5° down @ the drivetrain/trans output shaft, .8° down @ the d.shaft, & 2.4° down @ the pinion. I feel this is going to be my best compromise.

The driveshaft places want 3° down @ the trans, level or <1° down @ the d.shaft, & 3° up on the pinion. That 3° up @ the pinion would require me to raise the trans/drivetrain a substantial amount within the chassis so that the trans output is higher than the pinion in order to achieve their 'targets'. I don't wish to raise the drivetrain any higher than it is & I certainly don't want to build an entire new floor.

I'm going to try the final angles I ended up w/today. If there are vibrations, I can do the dbl cardan/CV joint up front & raise the pinion close to level (<.5°) per PB's recommendation. Also during all this measuring, I realized my ride height was a little lower than what I originally thought it was. I've been saying it was 5.5" @ the front cab mounts & 6.25" @ the rears. I'm actually 1" lower @ each w/the lower a-arm bolt C/L @ 6" off the ground .

I went ahead & made some pieces to raise the ECE x-member hoop & got the materials to make the trans mount spacer. I'll get this stuff fabbed & hopefully welded up next week after work.

Well, I've made some progress but no pics yet. I've been working on the trans spacer & in my measuring process to ensure everything was correct/repeatable, I found something wasn't....

I was told that sometimes you subtract the angles of the trans or pinion vs. the d.shaft & sometimes you add them. It was mentioned more than once that because my d.shaft was inclined from the trans to the pinion, that I had to add the angles. It was also recommended that I try & get the d.shaft level or angled down by raising the trans/motor. I worked on the d.shaft angle so it was no longer running uphill to the pinion. With that, I was subtracting my angles @ the trans to d.shaft as well as @ the d.shaft to pinion to get my previous numbers quoted above.

In my numerous set-up attempts, I realized my digital angle finder (DAF) could automatically adjust & compare the difference between two angles. I put the DAF on the trans output & then compared it to the d.shaft & my numbers matched what I expected & previously calculated. I repeated the process for the rear as well. I established the angle on the pinion, zeroed out the DAF, & then moved the DAF to the d.shaft. Instead of subtracting, I should have been adding.....

Ughhhhhhhhhhhhhhhh . . . ..... So, I sat there thinking it through again & realized that I should be able to do a simple tweak w/a shim & yield similar results. I removed a .250" shim which dropped the trans slightly thus bringing the d.shaft closer to level. This changed the front 'working angle' to 2.1°. The reduction of d.shaft slope meant adding less angle to the rear so I wound up w/a 2.3° working angle.

2.1° & 2.3° = less than 3° for good (normal) u-joint life. >3° angles are where many 'hot-rodders' complain vibrations become notable.
2.1° & 2.3° are within .2 of exact canceling angles.
The pinion angle was achieved w/o needing shims (w/the T/A mounts flipped).
This still allows for the CV-joint/1pc shaft set-up as my fail-safe.

Simple huh?

So, w/this all sorted, I noticed the d.shaft creeping up on one side of the T/A x-member hoop. I decided to get some measurements on stuff for verifications. I was relieved to see it was just all the up/down movement adding/subtracing shims @ the trans & loosening/tightening, wheels on/wheel off, @ the rear that skewed things slightly. After a quick nudge here & there, the trans is centered within the frame (& visually looks it); same for the rear housing (also 'looks' centered). With these confirmed, the shaft was closer to the middle (as close as it will get w/the slight pinion offset). Hopefully, I'll get an opportunity to finalize the trans spacer tomorrow. Then I'll take final measurements to determine how much the trans tunnel needs to be tweaked for clearance.

I also cleaned up an old set of sbc valve covers to work on my 'out of view' PCV system. Slow progress, but progress.

[VA72C10]

Progress? are we talking about progress?

[SCOTI]

Originally Posted by VA72C10

Progress? are we talking about progress?

I took multiple pics when documenting/adjusting all the angles. But the pics just don't show well. You can't read the DAF display because of the pic & I doubt you could tell a difference of the rear housing with & w/o shims.

It's been a tedious process to say the least....

[SCOTI]

Ok, pics & info for the hounds. I got the trans spacer finished today. Painted it & the shims I'm using to dial in the front working angle for the drive-line....

[SCOTI]

Here's an 'exploded view' of the shims, spacer, & poly trans mount w/hardware plus everything installed....

[SCOTI]

While in between coats & waiting for paint to dry, I prepped all the truck-arm x-member pieces (prep = stripped to bare metal). I had already cut & trial fit everything for raising the d.shaft hoop. I got everything welded up & then did post welding 'clean-up'....

[SCOTI]

Then I installed the trans mount/spacer assembly & d.shaft. I took a measurement @ ride height & had a little over .750" clearance. There's about .1875" clearance @ max drop/compression (air'd out)....

[SCOTI]

And the 'working angles': 2.4° @ the front (trans to d.shaft); 1.5° @ the rear (90°-88.5= 1.5°; pinion to d.shaft); & the descending d.shaft slope from the trans to the pinion....

[VA72C10]

Nice!!!! Thanks for the pics. Us hounds appreciate it

[lolife99]

I'm still trying to get my head around all these angles.
Thanks for posting pics also.

[lolife99]

Scot,... assuming the ECE trans crossmember positions the transmission in the stock location,... how tall is your combination of spacers at the tail shaft?
I'm also keeping in mind that the Dropmember raises the engine one(?) inch higher than stock.
I guess I'm trying to figure out how much you are changing the engine/trans installed angle compared to a stock truck.
Seems like the tailshaft is much higher.

[SCOTI]

The ECE x-member is in a 'stock' location as in I was able to utilize factory holes in the frame rails for the mount hardware. The total height of the trans spacer is 3.5" which includes a 3" block, a .250" trans mount spacer, & a .250" shim to dial in the exact height I want.

I recall Nathan saying the motor is moved up about 2" & forward about 1.5" w/the Dropmember/sbc combo. He also recommended setting the trans @ 5° down. A 2pc driveline would mean no cab cutting; 1pc driveline = clearancing req'd (less clearancing needed on 6x-66's vs. 67-72's).

With the 2pc driveline set-up per Nathan's recommendations, it would work. Even though it would work, it would not be ideal (there in lies the catch-22; we're dealing w/extreme drops & their subsequent extreme angles). There's no achieving 'perfect world' angles w/these extreme drops. That being said, I priced a 2pc driveline from 2 different sources & the quotes were $600-700 (price included new yolk, balanced front shaft, balanced rear shaft, 1310 F/R u-joints, HD carrier bearing, & CV or slip joint (w/warranty).

At $600+ bucks for a functional compromise, I decided to spend much less, trim the cab, & have the same functional compromise. I also planned for a fail-safe. If my angles don't work, I can drop the trans a little more, use a CV joint, raise the pinion to near zero & Nathan says I'll be good to go. The 1pc/CV set-up also fits under my raised d.shaft hoop.

Also.... If I would have left my rear wheel C/L alone (instead of moving it back 1" to center it within the wheel-well), I wouldn't have to do anything to the current d.shaft I used for mock-up. I have another d.shaft that's slightly longer & will have it cut down to the necessary length.

[aggie91]

After reading all this again about the angles and what you did, I now have a headache...

I think all your work is going to pay off big once you get it all together and having fun driving it. Makes me think that I need to revisit my driveline angles once I decide what my ride height will be this time...

So, When is the cab going onto the chassis?

[SCOTI]

And the dance continues..... one step forward, 2 steps back.

I had the morning off so I made plans to be @ a local d.shaft joint when they opened up. I brought 2 shafts w/me. One of them was the one I have been using for mock-up; the other was an extra that was about 6" longer.

I taped & marked the mock-up unit to allow quick & easy measurements from a reference point on the shaft. I explained that the shaft was used in my mock-up process & physically fit but was just barely too short in my mind (quick glance was 50% engagement of the output shaft). They wanted the measurements from the trans output shaft tip to the end of the u-joint flange. I explained I didn't measure but that I wanted the 'new' shaft to be 1" longer than my mock-up unit. He took some measurements of the 2 units & cut the longer one down. Welded + balanced w/some fresh u-joints & I was on my way. I did pause for several moments because although the new shaft was shorter than before, it sure looked to be greater than 1" longer than the mock-up unit. I decided it was my eyes playing tricks & headed to the shop.

I got to the shop..... my eyes were correct. The new shaft would not (could not) physically fit between the trans & rear pinion even w/the d.shaft yoke fully bottomed out on the trans output shaft. I called them to break the news & the shop foreman repeatedly said "this is why we have our customers measure the distance between the trans output shaft tip to the end of the u-joint flange...... It eliminates these mistakes." So I measured exactly as directed. I even took reference pics of where I was measuring from.

I got back to the d.shaft place & explained that there must have been some confusion between the builder & myself. I again said the new unit needs to be about 1" longer than my mock-up piece & that it should be easy enough to figure overall lengths & handed them the dimensions of my set-up as requested.

They whacked another ~1.5" off the d.shaft, re-welded, & re-balanced it. I also paid an additional fee because after all, if I would have provided the requested dimensions initially, it would have been right the first time.

I drove back to the shop to install the 'new.2' shaft...... Viola..... it doesn't fit. Now, 'new.2' is closer to going in.... but it doesn't. Again, w/the yoke fully bottomed out on the trans output shaft, the pinion end is just barely is too long (.125" maybe) so you can't seat it in place.

I placed the 'new.2' shaft next to my mock-up shaft..... it's about 1.x" longer (still not 1" longer). I can see now how those critically important dimensions helped so much. [/sarcasm]

2 trips (min 30mins away) to down-town Dallas.
Paid for shortening the same d.shaft twice.
3/4 tank of gas.

I'm still using the mock-up d.shaft. I took better measurements & have about 60% of the d.shaft yoke engaged on the trans output shaft splines. I'll live w/that vs. another trip.....

The guy that worked on the shaft was great to work with even though this was an excersize in futility (I'd buy him a beverage or 2 if I saw him out on the town). It would however be nice to serve some 'crow' to the shop foreman w/his repeated "this is why we do it this way" comments so I'll prob go ahead & call Monday just to poke a hole in his sails.