wayno Posted April 6, 2013 Author Report Share Posted April 6, 2013 Only the late L series 4 speed longshaft case will work though, I don't believe that a early/stock shortshaft 4 speed case will work, it's a different tranny. You will also need to remove the big cluster gear bearing on the 85/86 shortshaft 5 speed, and put the small bearing on, as the early 720 L case(80-83ish) has a small bearing. I have been told that the 620 5 speed case will also work, but I have never tried it, so I don't know that for sure. It's not cheap when you need two transmissions to make one good one, that is why I used to pull both trannys in the same wrecking yard, and make the one I needed right there out of the two, and just pay for the one I wanted, they had no idea I was doing that. Quote Link to comment
datzenmike Posted April 6, 2013 Report Share Posted April 6, 2013 The L 4 and 5 speed 71B front cases are exactly the same. Usually the reverse switches are in the same location but some 4 speeds are about an inch to the rear. These you would have to plug and drill and tap a new hole. Or just look for the correct 5 speed case. Never seen an L or Z five speed that didn't have the reverse switch here... Here is a 4 speed case that was plugged and anew hole added just forward of it. I've never seen one but just watch for them Quote Link to comment
Laecaon Posted April 6, 2013 Report Share Posted April 6, 2013 Is there a seal for between the front and rear casing? Or do you use RTV? Quote Link to comment
jrock4224 Posted April 6, 2013 Report Share Posted April 6, 2013 I used a 620 5 sp bell on my short tail 720 transmission from a 86 standard cab....it was a much easier swap to do, then I convinced myself of in my mind...with both trannys on the work bench it took about a hour and that was double checking this thread for proper procedure.. ...the only thing left is swapping the speedo gear which I should have done on the ground then in the 521 Quote Link to comment
datzenmike Posted April 6, 2013 Report Share Posted April 6, 2013 I used a sealer. It isn't RTV exactly and was silver. Have to wait 10 min before assembling to allow it to set up. RTV is rubbery and this stuff is firmer. Quote Link to comment
Laecaon Posted April 6, 2013 Report Share Posted April 6, 2013 I ask because I noticed my spare dogleg tranny is actually for a Z series motor. So I will need to swap front cases. Also, I have seen some sources saying that the Z dogleg has different gear ratios than the L dogleg. Specifically Im most worried about 5th gear as it looks to be less of an overdrive (barely) Quote Link to comment
wayno Posted April 6, 2013 Author Report Share Posted April 6, 2013 I have never used anything between the two cases, and they have never leaked on me to date, but they are clean before I put them together. If you do use something, use very little, just a light film. Quote Link to comment
I'm BLUE Posted April 6, 2013 Report Share Posted April 6, 2013 Anerobic Sealer is pretty good stuff. Quote Link to comment
datzenmike Posted April 6, 2013 Report Share Posted April 6, 2013 There are two different gear sets for the 63A dogleg. One for L series and another for the Z series.The Z series were only on the 80-'81 A10 (later HL510) 3rd, 4th and overdrive ratios are exactly the same. First and second are slightly closer together on the Z series. Quote Link to comment
jrock4224 Posted May 27, 2013 Report Share Posted May 27, 2013 So I need a tail shaft out put seal.....does anyone know the part number off hand for the 84/86 shortail teansmission so I can make sure I get the right one Quote Link to comment
datzenmike Posted May 27, 2013 Report Share Posted May 27, 2013 32136-U0100 used from '71 through the Xterra. I find the NAPA one is thinner and can be (carefully) driven into the tail a little further than the stock thicker one. This places the seal lips on a fresh section of driveshaft spline so it seals better. Always lube before shoving it in. Quote Link to comment
MicroMachinery Posted May 27, 2013 Report Share Posted May 27, 2013 Always lube before shoving it in. ^This Quote Link to comment
Lobo Posted May 15, 2014 Report Share Posted May 15, 2014 so what throw out bearing and arm do i use for this swap in my 521 Quote Link to comment
wayno Posted May 15, 2014 Author Report Share Posted May 15, 2014 so what throw out bearing and arm do i use for this swap in my 521 As far as I know, the arms are all the same, it's the throw out bearing collar that is important, you need to have the collar made for your clutch cover/pressure plate. Quote Link to comment
Lobo Posted May 15, 2014 Report Share Posted May 15, 2014 So you match the throw out bearing to the clutch not the tranny if I'm understanding it right Thank you Quote Link to comment
wayno Posted May 15, 2014 Author Report Share Posted May 15, 2014 So you match the throw out bearing to the clutch not the tranny if I'm understanding it right Thank you Yep :) Quote Link to comment
Lobo Posted May 15, 2014 Report Share Posted May 15, 2014 I know this was a old thread but thank you for your help I just built a 5 speed with a 4 speed bell housing from a 76 620 and a napz 5speed from a wheel drive 720 can't wait to get it in the truck Quote Link to comment
wayno Posted May 15, 2014 Author Report Share Posted May 15, 2014 I know this was a old thread but thank you for your help I just built a 5 speed with a 4 speed bell housing from a 76 620 and a napz 5speed from a wheel drive 720 can't wait to get it in the truck Are you saying you made a shortshaft 5 speed out of a 4WD shortshaft transmission? Does it have a speedometer drive connection? Quote Link to comment
jrock4224 Posted May 15, 2014 Report Share Posted May 15, 2014 i have speedo connection on my two wheels drive short tal but been able to find a speedo cog/transmission to give me even a semi close speedo reading Quote Link to comment
Lobo Posted May 16, 2014 Report Share Posted May 16, 2014 Should have proof read no 2wd 720 Quote Link to comment
wayno Posted May 16, 2014 Author Report Share Posted May 16, 2014 OK, your good then, it has a speedo drive. Your trans mount will need a mod, and if your going to use your 4 speed yoke, you will need to put a soft plug in the hole so it don't leak gear lube. Quote Link to comment
Lobo Posted May 16, 2014 Report Share Posted May 16, 2014 I grabbed the hole driveline I wounder if I can just use that it is a one piece I'm lowered so I think there would be no issue with cross member just hope it is the right length Quote Link to comment
ggzilla Posted May 16, 2014 Report Share Posted May 16, 2014 There were 10 different driveline links for the 720. Quote Link to comment
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