thelow620 Posted March 13, 2019 Report Share Posted March 13, 2019 Been on the search for a 5 speed to put in my 77 620, which currently has an L20 and 4 speed combo. I came across an ad for a complete 1982 z24 and 5 speed transmission for sale for a decent price. I've been trying to find info about using this trans and this quote below from datzenmike was good info. If I'm reading this correctly you use the L20 bell housing from a 5 speed on the napZ trans to correct the lean angle. Can I assume I can also use the bell housing from a 4 speed as well? Thanks. "The KA or the Z series transmission will physically bolt to an L series motor BUT it will be rotated about 20 degrees to the right with the shifter in the passenger side seat. the rear transmission mount will also be tilted and not bolt up. Not a good idea. You can take the front case half off an L series FS5W71B and swap it onto the KA or Z series transmission and this will 'convert' it for use on an L series motor. Keep in mind the the transmission doesn't care what clutch you use. It has no effect what ever on the transmission. The clutch used it totally dependent on what flywheel you have. Car L20B use 200mm bolt pattern while trucks use 225mm. The flywheels look the same it's just the pressure plate mounting bolt pattern that is different." Quote Link to comment
datzenmike Posted March 13, 2019 Report Share Posted March 13, 2019 Yes but check the following first. Now I've never seen this but at least one 4 speed had the reverse light switch mounted farther back and this won't work on a five speed. The picture below is the correct location for the reverse light switch, just behind the clutch dust boot on the passenger side. You can see there is a raised boss just to the left of it. I wouldn't worry, but just to be sure check. Would not be hard to Black & Decker a new hole and tap it so it looks like the above. You could plug the old hole with the left over reverse switch. One other thing, is this an '85 or '86 transmission? If yes, it will have a 62mm counter bearing that will be too large for your smaller 56mm hole in the front case. If you can afford to have the case milled out you can take advantage of the much improved larger counter bearing. If not, just pull it off and swap your 56mm one on and go. All that's needed is a gear puller and hammer it on with a suitable sized pipe that just fits the inner race so you don't bugger the bearing. Quote Link to comment
thelow620 Posted March 13, 2019 Author Report Share Posted March 13, 2019 The seller says it's out of an 82 720. I'll check my 4 speed to see where the reverse switch is. I'll probably go pick it up after the Eaglerock meet if I dont find a transmission there. Thank you. Quote Link to comment
datzenmike Posted March 13, 2019 Report Share Posted March 13, 2019 The '82 had Z22 engines so maybe the Z24 was swapped in.. maybe with the 5 speed also. Maybe the seller thinks it's a Z24. Quote Link to comment
thelow620 Posted March 13, 2019 Author Report Share Posted March 13, 2019 All situations are possible. I'll just be happy to have overdrive. You dont happen to have gear ratios for this trans handy do you? Quote Link to comment
datzenmike Posted March 13, 2019 Report Share Posted March 13, 2019 If you get it, mark the input and output shafts, say at 12 o'clock on both. Place in first gear and have someone count to output turns while you turn the input 20 times. 5.5 turns you have a 0.813 overdrive. 18.7% 6 turns you have a 0.833 overdrive ratio. 16.7% Make sure it has a speedometer drive in it. 4X4 transmissions are driven from the transfer case and cannot be made to work the speedometer. Quote Link to comment
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