Just sold my little fishing boat. Now I can buy the new rear end that I've wanted!!! So, I know~ I should probably wait until I've done this to post about it, but hey, it's me. Anyway, this Saturday I shall head over to Joplin and pick up said rear. I will update this thread (with pictures) as the work progresses.
No worries. I post things that I wanna do or plan to do all the time. It's just executing the plans that seems to be the hang up! Looking forward to seeing the new axle under the truck. What did you choose, by the way?? Damon
Seriously~ I'm just stunned that after A-L-L these years of, "I'm going to..." or, "I want to..." I finally AM!!! As far as the axle, it will be a Colorado. I assume with drum brakes. I still need to call the company that put out my master cylinder and see if it's disc/drum or disc/disc. All I have is the CP parts number, and it doesn't say. (It was a birthday gift, ya know...)
REMEMBER Zig... The axle hub diameter of the Colorado/Canyon rear end is larger than the axle hub diameter of our trucks. Original wheels will NOT fit over the larger hub. The bolt pattern is the same (6 on 5.5) though. The Colorado rear end I installed is from a 2WD truck. 4WD may be wider, I don't know. I will employ spacers to position my wheel/tire combo between the bedside and the fender. If you end up going the spacer route yourself, make sure they a lug-centric AND hub-centric. Or, if the width is good, you may opt to just pop the axles out, and have the hub diameter turned down. There is enough material to support this modification. Since you'll have to pop all the wheel studs out (they are a straight spline) to have the hub turned, it is a perfect time to replace the studs so they aren't metric. Spring perches are available from off-road type suppliers, and you'll need a crash course in driveline math. Here it is: 1. SIDE VIEW: Whatever angle the engine/trans points DOWN, the pinion shaft must point UP at the same angle (there IS some tolerance here, but for the sake of argument, lets just say they need to be the same). 2. TOP VIEW: The pinion faces straight (forward), regardless of where it is located in the rear end (often offset, and it IS offset on the Colorado rear). The engine/trans MUST face straight (back), regardless of whether or not it is in the center of the frame (you aren't changing this, so you're OK). Thats the crash course. I bought several books on driveline fab/transplanting, and they wax poetic page after page explaining those two rules. Here's the Cliff Notes: Angle UP=Angle DOWN, Angle left/right=zero. Following these two simple rules (well, there are angle minimums/maximums which must be considered, but they don't apply here for you) makes for happy U-joints. The issue is U-joints are not constant-velocity joints (FWD cars have "CV" joints), so angles must be equal to cancel each other out. You'll need a new driveshaft too, and take a good look at the slip yoke to see if it needs replacing at the same time.
Thanks, Mike! I sent you a PM begging for a measurement. It, of course, is life or death. It was fun looking at your progress pictures again! Is your 2wd disc or drum brake? Thanks!
Zig, I've been meaning to ask you that question. Are you going disc or drum on the colorado rear? Looking forward to "build" pics on that. Glad to see your re-newed vigor! Ken
Had a nice chat with Mike (52wasp) last night! He was able to confirm some items of interest for me that set my mind at ease. Another reason why this site is so popular? I just need to check on what my master cylinder is set up for, because I assume they aren't open for suggestion and that they actually had a specific setup in mind when they were designed. other than that~ full speed ahead! I don't have a problem going drum brakes at all. The only problem that will need to be addressed is that the hub is bigger than the opening on the wheel... by just a bit. No biggie, just have to get creative.
Zig, it was nice to talk to you! I hope you march into the salvage yard armed with the knowledge to buy exactly what the old girl needs. As soon as I get a major side-job behind me, its back to wrenching on Penny for me too! Interesting to hear we both have a similar "need to complete by" date.
Same here, Mike. I will be picking up a G80-373 Colorado rear end. $375 with tax. Only friggin' problem is, THEY'RE CLOSED ON THE WEEKEND!!! ArrrrggggH! That means I'll have to split right after school, zoom over there and (hopefully) get it loaded so I can return before my bedtime. (8:30 is late, since I get up at 4:20) Big brother, drums it is! I like drums. And guitar. Keyboards aren't bad either...
Rear end is OUT! Well, at least I could take the old ~heavy~ rear end out while I wait to get the new one. I want to cut off the shock mounts. Not sure if I want to cut off the old perches. I don't know right off if the diameter of the axle on the Colorado would make these useable. The frame is sitting on the jack stands, but just to be safe, I put those old split rims to use on top of railroad tie pieces. (You can never be too safe, right?) I mean, with the tunes crankin' it just might vibrate off those stands, and then what~ Anyway, pictures as promised.
Lame brain~ Alright~ Pinion angle time... Here was my thinking on a shortcut to setting pinion angle. First, I knew the ass end would be gone, but not the drive shaft. Sooo, I decided to make a cradle for it to stay just exactly the angle it was in when the weight of the truck was fully on it. Next, I took a handy dandy straight edge and put it on the center line of the pinion. The straight edge was long enough that I was able to transcribe the line onto the side of the cradle. Then, I'm thinking once I have my new rear end, I'll walk around proudly! Er, wait~ I mean I will put some wheels on it, roll it under the truck, place the perches on top the axle right where they are supposed to be. (spacing copied from original axle) (BTW, the yoke on the pinion seems to extend exactly as far as the original...) Put the weight back on it then raise the pinion to match the scribed line, have someone come and tack them in place or just outright weld them in place. Taadah~ Lame brain, or what?
Paul, The logic certainly makes sense to me, but the OCD in me would still want to check the driveline angle at the transmission, then double check the measurement (whatever it will be with your scribed line) to see if they match. Just my ultra-cheap two cents. Damon
Pinion Angle This is a bit out of my depth but I seem to recall using a cheap bubble gauge against the pinion flange and trying to keep it @ 3 degrees.... Anything Evan or Russ says here surpasses my Farm Fixin' ways .
More like 5 something The ass end in this old truck wasn't for speeding down the highway, just pulling homes off their foundations.
The theory is to measure the angle downward from the tranny, and match that angle upward for the rear end. A racing buddy showed me to add a few degrees downward on the rear, when you gas it, the truck will lift instead of squat, leveraging the power down.
