Rembrant Posted May 22, 2022 Share Posted May 22, 2022 Gents, I soon have to have a custom drive shaft made, and in order to measure the length, I need to know how far to insert the slip yoke into the tail of the transmission. The slip yoke I have is not original to the transmission, but it's supposedly out of a '98 F150 2wd with a 4.2L, so I'm assuming it was either an M5OD 5spd or another 4R70W like the one I'm installing in my truck. Anyway, that doesn't matter. There's a rust line on the yoke so I know where the travel ended, but I don't know how much that travel was. I'm guessing between a 1/2" and 3/4"?? This truck will be sitting fairly low, with a pretty limited suspension travel...and it will never be used to haul any weight in the bed other than the odd lawn chair or duffle bag. Anybody know what that should be? Or if you happen to have a 2wd with an AOD, how much of the exposed slip yoke is shiny?? lol. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 22, 2022 Share Posted May 22, 2022 I don't know the answer to the question, but I think I'd determine the maximum depth it can be and put it at 1/2 that when the truck is sitting on the ground. Then I'd lift the truck up and see where that puts it to make sure there's plenty of engagement - although you shouldn't be transmitting much power when at full droop. And then assume that the distance it moves from full droop to sitting on the ground is what it would do in full compression and see if there is enough range of movement for that. Link to comment Share on other sites More sharing options...
Pete Whitstone Posted May 23, 2022 Share Posted May 23, 2022 The only data point I have on that situation is when I have had custom driveshafts made, the driveshaft guy told me to push the yoke in all the way, pull it out an inch, then take the u-bolt center to center measurement. So far, that has worked out ok. I could see if you have a truck that sits way up high with a big angle on the drive shaft, and then you dump a ton of rocks in the bed, it might compress the suspension enough to bottom the yoke and cause a problem. But that's not my truck, and it doesn't sound like it's yours either. Link to comment Share on other sites More sharing options...
Rembrant Posted May 23, 2022 Author Share Posted May 23, 2022 The only data point I have on that situation is when I have had custom driveshafts made, the driveshaft guy told me to push the yoke in all the way, pull it out an inch, then take the u-bolt center to center measurement. So far, that has worked out ok. I could see if you have a truck that sits way up high with a big angle on the drive shaft, and then you dump a ton of rocks in the bed, it might compress the suspension enough to bottom the yoke and cause a problem. But that's not my truck, and it doesn't sound like it's yours either. Excellent info guys, thanks. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted May 24, 2022 Share Posted May 24, 2022 The only data point I have on that situation is when I have had custom driveshafts made, the driveshaft guy told me to push the yoke in all the way, pull it out an inch, then take the u-bolt center to center measurement. So far, that has worked out ok. I could see if you have a truck that sits way up high with a big angle on the drive shaft, and then you dump a ton of rocks in the bed, it might compress the suspension enough to bottom the yoke and cause a problem. But that's not my truck, and it doesn't sound like it's yours either. Yep thats how I was told to do it from the drive shaft shop. Weight on the suspension, in all the way and pull out 1 inch and measure. If I did seat to seat on the joints I told the shop the same they then could figure it out from there. Dave ---- Link to comment Share on other sites More sharing options...
mat in tn Posted May 25, 2022 Share Posted May 25, 2022 The only data point I have on that situation is when I have had custom driveshafts made, the driveshaft guy told me to push the yoke in all the way, pull it out an inch, then take the u-bolt center to center measurement. So far, that has worked out ok. I could see if you have a truck that sits way up high with a big angle on the drive shaft, and then you dump a ton of rocks in the bed, it might compress the suspension enough to bottom the yoke and cause a problem. But that's not my truck, and it doesn't sound like it's yours either. Yep thats how I was told to do it from the drive shaft shop. Weight on the suspension, in all the way and pull out 1 inch and measure. If I did seat to seat on the joints I told the shop the same they then could figure it out from there. Dave ---- I did this two weeks ago. I had my driveshaft cut down. I inserted the yoke all the way in then measured how much was needed to be removed in order for the rear u joint to make it into the pinion yoke. it happened to be 1"clearance that was needed. same results but measured a different way. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 25, 2022 Share Posted May 25, 2022 I did this two weeks ago. I had my driveshaft cut down. I inserted the yoke all the way in then measured how much was needed to be removed in order for the rear u joint to make it into the pinion yoke. it happened to be 1"clearance that was needed. same results but measured a different way. Matt - Was the truck on the ground or on stands? Link to comment Share on other sites More sharing options...
mat in tn Posted May 25, 2022 Share Posted May 25, 2022 Matt - Was the truck on the ground or on stands? sitting on the ground with weight on the frame to simulate a load. "Compressed range of motion". Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 25, 2022 Share Posted May 25, 2022 sitting on the ground with weight on the frame to simulate a load. "Compressed range of motion". Link to comment Share on other sites More sharing options...
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