I have used cut down ones many times without regret/problems. Have a friend/machinist do them for me.
had a local guy do em' in the 70's for dirt mods, went to school on his method, still serves me well if I gotta build one.
The only drive shaft I was ever able to use without cutting it down was from a 72 Nova and I also used the rear axle under my '39 Ford convertible. HRP
Got a couple Jeep Cherokee driveshafts hanging in the storage bin that might be handy for something...
I use to have them made for me, then I decided to try it myself and to my surprise, they worked. Then I got smart and ordered one of these last time, and never looked back... https://www.summitracing.com/parts/axe-212010x10295/overview/
They want a fortune to shorten a shaft around here. Ordered one from Speedway. Way less money. Sent from my SM-T350 using The H.A.M.B. mobile app
1.Hack saw the yoke cup weld ctrline just tubing thickness deep, all the way around. 2. Mark&cut tube, file Sq. to new length. 3. Peel away the short shaft stub from the cup weld cut. File/Dress the flange revealed. 4. Phase/align yokes, hammer yoke in, tack (3x) & weld.
Yep! Front half of an old dodge with the trunnion with an open drive banjo in the rear. Plus a custom leather trunnion boot.
I still have a pretty large pile of driveshafts from some of the many Mopars I've s****ped out over the years. I usually shorten my own, never had a problem with them, and I shortened a lot of driveshafts for me and others. The biggest problem is you can seldom take more then 3" off the length, so you need to cut down shafts that are close to the length you need. The pile of "normal" length shafts is getting pretty small, but I still have a pretty large selection of large diameter, long drive shafts here. Gene
That's what I had to do to mate up to my flathead dodge six and three speed forty dodge pickup trans to a forty ford banjo.
I understand , fully . It that is what it takes to get you rollin , that’s what it takes . I just haven’t ever used one . I have just tossed them , thinking they were worthless . I have learned they maybe treasures I have tossed. I like the boot on yours that is neat stuff there .
Measuring tape at the junk yard. Coupster; 8" Ford rear/course spline aluminum PG, front half of a '69ish Econoline, "U" joints all the same. '57 Chevy PU, 9" from '77 MK V(?)/TH400, '79 Firebird, mix and match "U" joints from NAPA.
Cut down more then a few my self an 4 others,many times it took 2,to make one with the right ends. That made the pile have some odd cut 1/2 ends in it as well,some got used an a few got trashed. For sure getting a lot harder to find. Some newer cars use rubber joints.
In the early 80's I had a small salvage yard until the county dissuaded me from continuing but I had saved quite a few of the drive shafts but after a move or three they dwindled down. I have a few left but I used the last "long" one for the Stude and it barely made the cut This is probably my last build so maybe my supply of drive shafts turned out about right.
There is a whole lot more to making a driveline than cutting off the tube and hammering the yoke back in and welding it. I worked in a driveline shop for awhile before I arrived at my current job. Just a few items include: matching the correct yoke to the correct wall thickness of the tube, getting the yokes in phase, making sure the shaft has no more than .010” runout on both ends, and getting the proper gap between the tube and yoke for welding. If everything is done correctly, usually no balancing is required. If a shaft is dropped or clamped in a vise, it’s bent. If you strike the tube with a hammer, it’s bent. Most people have no idea how fragile a driveline tube is. On car shafts, wall thickness is usually only .65” or .083”. It takes very little rough handling to bent tube that thin. Even on cl*** 7-8 trucks, wall thickness is .134, .180, or .259 on really heavy severe duty stuff. Bear this in mind, on big trucks, the driveline is designed like a fuse, it’s supposed to break before an axle shaft or differential. One last thing, for all you guys using presses, vises, and ball joint presses, it’s super easy to collapse a yoke. Even a few thousands will result in a snap ring that will not fit properly. Lay the trunnion cross on a vise that is opened to fit, and tap on the yoke ONLY to drive the cap up and out. Turn it over and repeat. Be sure to remove the grease fitting first. Clean the inside of the yoke up, and insert the cross into the yoke. Hold up on the cross and carefully tap the cap into the yoke. Set the snap ring, and turn it over and repeat. After setting the last snap ring, put the caps on the cross, lay the freshly installed u-joint on the vise again and tap the yoke on each side to set the caps against the snap rings. Lube and install. Sent from my iPhone using The H.A.M.B. mobile app
That’s why I use the vise to install the cups and not my air over hydraulic press. The press has no “ feel”. With my vise the caps , usually, push in very easily, but if something is amiss, I can “ feel” it in the handle and check it out. I usually try the hammer method to remove the cups, as it is faster. But if I encounter problems, I don’t like to beat on a driveshaft with a BFH. When in the press, I support the drive shaft in such a way as to put no pressure on the yoke of the driveshaft itself. I’ve done a lot of u joints in my career. The only ones I ever had problems with were the ones that I was not the first to change the u joint and had some one mess it up, before I was there. And I can usually fix those, too. Bones
Using '60's shafts, yokes and a carpenter's framing square, juke box welder, I have shortened 10 straight tube shafts. No probs w/vibration or eccentric behavior.
My uncle was a log trucker and we were about 20 miles from the blacktop coming up out of the woods with about 100,000 lbs. on and it was about a 10% grade. That turbo started to huff and puff and jumping up and down and it wound that drive shaft right up in a mater of seconds before he could clutch it! We fixed it in the field and we had all we could do to get it moving again with out a repeat. Thought we were going to have to unload part of it first.
It can be explained how precise and exacting the process is to cut down a drive shaft, but leaver it to hot rodders to do it time and again and achieve the desired results, a non-vibrating drive shaft, and moreeoften than not without any vibration. I have never had to add weights but realize you have to do it correctly, I bought a project car and it took me a couple of yours to get the car to the point it could be drive, or that's what I thought. It seem the previous owner had tried to shorten the driveshaft and like 95% of the work he did it was substandard, the front yoke was installed out of phase, that car shook so bad I couldn't hang on to the steering wheel. HRP
When I built my sedan, I needed a 29 1/2" shaft that fit a T-5 to a 9". So I went to the salvage yard and found a Trans-Am donor with the shaft still in it. I believed it was a factory shaft. I got it for 45 bucks and was happy. I took it back to the shop and cut it down and put the correct (harvested/used) yoke for the 9" on the other end. I put the yoke in the trans and tacked the other yoke after spinning it in the car and bumping it with a plastic mallet to center it. I put a dial indicator on it and my end was perfect and the factory end was out .030"! It had 3 weights welded on the trans end and I was kind of befuddled, but thought I would try it first. Believe it or not, it ran smooth without vibration! I ran it that way for several years, but it took me all day to go to the salvage yard, cut it off, set it up and weld it. It always bothered me and I'll never do it again. I'll buy a brand new Fast Shaft for around 200 bucks from now on, which is what I ended up doing. I sold the old cut down shaft at the swapmeet for 50 bucks.
I priced having a new driveshaft built locally and they wanted almost 700 bucks, I figured they just didn't want to fool with the hot rod crowd when the majority of their business is big equipment. HRP
Our driveline spe******t at work also does drivelines at home. He does top quality work so I send a lot of side jobs his way. When I need something done he treats me pretty good...
In my opinion, driveshaft's are as good as gold and silver. I keep each and every one. The driveline service here charges $50 to shorten and balance them. I've had them build a new shaft with me supplying the ends and that's always around $150. The only issue I've had is making sure i use the correct shaft for the application because apparently not all tubes are created equal lmao!
I always like looking at those twisted and mangled displays at driveline shops, trying to conjur up the sound they must have made. I'm betting a big percentage of homemade driveshafts that gave no problem were partially derived from pure luck. I can say this partly because I too worked for a while in an automotive machine shop doing the "cut apart" end of them on a lathe but never the "go together" part, I think they (smartly) figured I didn't have enough experience yet, they were right. One of the very first things done on my new 18x80" home lathe and Miller 200 welder was build a driveshaft for my 66 Suburban replacing the original two-piece shaft. I was pretty proud until I went to get it from being balanced and they told me they had to redo it. A little story I have told before was when still in high school a friend put a real 327/365 hp engine and B&M 4 speed hydro in his straight axle 50 Chevy coupe, as he had come to the end of his money he chose to build a driveshaft himself from two wrecking yard shafts. This was the most cobbled up thing as he had **** welded the two pieces of tubing together after shortening and welded it with another friends' Lincoln "buzz box". Suffice it to say it was a major "fail".
The Jalopy Journal
