tranny help

[curtile13]

Hey guys I have a regular cab 1980 720 with a 4 speed. I picked up a 5 speed out of an extended cab 80 that I plan on putting in but have a few questions. Will I run into anything when putting it in? Also what size of pressure plate and clutch goes in it? All help is appreciated

[ggzilla]

Use the same clutch you have now. Measure the new transmission -- if it is the same length as the four speed, just bolt it in. If it is different length, search for the correct factory shaft. They changed the transmission every other year, so best to measure your two.

[wayno]

Please post how this turns out. wayno

[datzenmike]

Use the same clutch you have now. Measure the new transmission -- if it is the same length as the four speed, just bolt it in. If it is different length, search for the correct factory shaft. They changed the transmission every other year, so best to measure your two.

 

Good advice.

 

On the clutch arm on your 4 speed is a release bearing and housing that holds it. Make sure you us this one on the 5 speed.Be sure to use a new bearing but keep the housing.

 

Both housings, 4 and 5 spd, should be the same but just to be safe use your 4 spd one.

[curtile13]

Ok will do...out of curiosity why should I use the one off my 4speed?

[datzenmike]

Ok will do...out of curiosity why should I use the one off my 4speed?

 

 

The housing that holds the bearing is matched to the pressure plate size. The other transmission may have had a different size PP and so would have a different housing size that wouldn't work on yours. As I said they likely are the same but we know yours works with your PP.

 

Make sure you pull the old bearing off and press on a new one. It's a high wear item, fairly cheap, and you don't want to have to remove the transmission in six months time to replace it then. The bearing comes dry so you have to fill it with grease. Wheel bearing grease will do. Put a blob in the palm of one hand and bress the bearing into it in a scooping motion to press the grease into it until filled. Wipe off excess and install on the housing.

[curtile13]

Ok will do. also what is the difference between the sizes of clutch and pressure plates? I was told that they come in 8 7/8" and 9 1/2"

 

 

[datsunaholic]

The clutch/pressure plates are 225mm for a 1980 truck. There were other sizes- 200mm and 240mm, but neither were used in a 1980 truck.

[datzenmike]

Yeah I wasn't sure. I pulled an L20B with a 240mm flywheel. It was a 4X4 and stuff was likely swapped on it.

[datsunaholic]

The info I have is all 720s had 225mm clutches up to 10/82, then switched to 240mm coincident with getting the Z24 (and Z20) engine. All the L20B and Z22 ones used the 225mm clutch. 2WD/4WD didn't matter.

 

However, weirder things have happened, and over time stuff gets shuffled around.

[datzenmike]

I have taken a 225mm from a diesel 720.

 

My info shows 240mm on all Z20 and Z24 720s. The '80 4X4 I stripped had a pre '78 L20B with manifolds bolted together. I figured all 4X4s had the 240mm clutches because of this.