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5 speed swap from hell


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I've been working on this for a week now and still can't figure it out and feel bad for bugging Mike

 

The stats:

1973 620

1975 L20b from a 610

1985.5? 5 speed via Mike

225mm flywheel (unknown)

and new clutch kit w bearing

 

2 release forks, old 4 spd and matching fork for 5 spd

4 collars, 200mm 4 spd, two 225mm collars (one is an 1/8th taller) and a 240mm collar from Lordco.

 

I have the L20 200mm flywheel, clutch disc and pressure plate.

 

The problem:

I can't get the release bearing close enough to the pp fingers to engage the clutch. By the time the release bearing is even on the fingers it's almost 2" between the fork and the slave at full extension.

 

I'm starting to need the truck and want to just put the 4 speed back in behind the bigger 225mm flywheel and clutch? Idk this is very visual based and hard for me to describe what I'm seeing.

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The clutch pressure plate, throwout bearing, and the bearing collar are matched to each other.  The transmission does not care what L-engine it is attached to.   The flywheel, clutch parts, and throwout bearing, and collar that worked before should work with any transmission.  

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Here are links for pressure plate and throw-out sleeve dimensions:

 

http://datsun510.com/photopost/showphoto.php?photo=13336&ppuser=263

 

http://datsun510.com/showphoto.php?photo=13332&title=throw-out-bearing-sleeve-dimensions&cat=3479

 

http://datsun510.com/photopost/showphoto.php?photo=6980&title=225mm-and-240mm-clutch-t-2fo-bearing-sleeve-specs&cat=3129

 

But when you say "...it's almost 2" between the fork and the slave at full extension..." it sounds like something other than the wrong TO sleeve length. Are you trying to use your original 4-speed or the 1985 5-speed? From about post #231 in your build thread http://community.ratsun.net/topic/41321-1973-620-new-year-new-questions-new-oics/page-12there is discussion of changing the front tranny case/bell housing on the '85 tranny so it will bolt up to your L20b. Have you changed the front case? Ignore the question if you are using your 4-speed.

 

I don't mess with trucks but remember something about some trucks having an adjustable push rod on the clutch slave cylinder. Does your slave have this? Someone who knows about the adjustable rod will have to chime in on this subject, cause I don't know if that could have anything to do with your malady.

 

Len

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Measure from engine block flange to installed and torqued pp fingers tips. then measure from trans flange to installed (on collar) TO bearing surface. both Measurements should b close to a match with correct lentgh TO collar installed

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The clutch pressure plate, throwout bearing, and the bearing collar are matched to each other.  The transmission does not care what L-engine it is attached to.   The flywheel, clutch parts, and throwout bearing, and collar that worked before should work with any transmission.  

 

The L16 and 4 speed had a 200mm flywheel, the L20 also came with a 200mm flywheel (and the donor 610 has a 4 speed). So if I want to go back to the 4 speed I'll just have to buy another new clutch kit cause I have all the working parts for that.

 

 

But when you say "...it's almost 2" between the fork and the slave at full extension..." it sounds like something other than the wrong TO sleeve length. Are you trying to use your original 4-speed or the 1985 5-speed? From about post #231 in your build thread http://community.ratsun.net/topic/41321-1973-620-new-year-new-questions-new-oics/page-12there is discussion of changing the front tranny case/bell housing on the '85 tranny so it will bolt up to your L20b. Have you changed the front case? Ignore the question if you are using your 4-speed.

 

I don't mess with trucks but remember something about some trucks having an adjustable push rod on the clutch slave cylinder. Does your slave have this? Someone who knows about the adjustable rod will have to chime in on this subject, cause I don't know if that could have anything to do with your malady.

 

Len

 

This is what I am thinking. I did try to use the 200mm 4 speed TO collar on the 225mm flywheel in the 5 speed transmission, not knowing you need to match the parts. Mike then sent me two TO collars, one slightly taller, 1/8th", AND I bought a 240mm collar from Lordoc because my coworker who used to race 510 remembers machining, or making spacers to get the TO bearing to work right.

 

This was a fixed push rod, and the 3 spare slave cylinders are also fixed. My coworker also remembers these, it was more the 510, roadster, and yes you make a rod that adjusts for the TO.

 

 

Measure from engine block flange to installed and torqued pp fingers tips. then measure from trans flange to installed (on collar) TO bearing surface. both Measurements should b close to a match with correct lentgh TO collar installed

 

I will be pulling everything out and trying this tonight.

 

It just seems like this clutch kit i bought isnt/is a weird size, and because it didnt come with a TO collar I cant make up the gap?

 

If I had to use the 4 speed, should I but a clutch kit for the 1975 610 the engine came from or the 1973 620 transmission behind it?

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Disclaimer to start - I've got a bad tooth tonight, probably heading for a root canal, so I may not be thinking clearly, but I'll try.

 

I don't see why you can't use your 225mm flywheel and new clutch IF you have the right sleeve for the TO bearing. The clutch kit you bought is for what year/model?

 

Here http://datsun510.com/photopost/showphoto.php?photo=6980&title=225mm-and-240mm-clutch-t-2fo-bearing-sleeve-specs&cat=3129it looks like there are 3 different size TO sleeves for the 225mm clutch. You said you have 2 different size sleeves for 225mm clutch, but maybe you need the 3rd size. Try matching the year of clutch kit you have with the sleeve sizes on the chart.

 

Of course this is assuming the clutch kit they sold you is what the part number says it is. New parts in a wrong box isn't impossible. But you can bolt the clutch to the flywheel and measure the height and compare it to the first chart I linked to and see if it matches one on the chart. Probably will but worth checking.

 

So did you change the front housing of the 5-speed with one from an earlier L-series compatible tranny?

 

Len

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For clarification the '73 620 had (almost) the same transmission as the 521 and the 510 wagon (an F4W63) with the exception of the clutch arm. These slightly newer, F4W63L 4 speeds, used in the early 620 and in all 610/710 and A10s did not need the adjustable pushrod and the hole in the clutch arm.

 

'74 saw the first use of the longer F4W71B four speed.

'77 saw the introduction of the optional FS5W71B 5speed. 

 

Both these transmission will physically interchange without any modifications.

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The trans was from a later 2wd Z24 720. The bell was from my '78 620. When it lost 5th and then 2nd (actually you could hold it in gear but f that) it was time to throw in the spare I found in a '79zx. That one is currently in my 710.

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When I went from a 225mm stock clutch and flywheel to a 240mm clutch and an aluminum flywheel in my SR, I first measured from the pressure plates fingers to the end of the crank shaft with some vernier calipers. Pulled the old clutch and flywheel out, installed the new and measured again and found the depth .100" less which told me I needed a taller TO bearing carrier. This was for a NA S14 SR20DE installing a Turbo clutch setup.

 

Like what guys have said, you're trans is fine. If you're going to pull it back apart which sounds like you have no choice first measure what you have installed then put the stock stuff back and measure as I did. If your difference is extreme I'd say wrong PP but I doubt it will be. If it's correct then you're clutch arm should be somewhere in the middle of the hole in the case it goes through and you should have just a hair of play before the TO bearing hits the PP when moving the clutch arm.

 

Are you using the same type of throw out bearing and what was originally in there?

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Using those charts that Len posted I measured my longest TO collar and its 52.5mm which is used on '74 and up 225mm clutches.

 

I bought a '75 clutch kit for a 225mm flywheel. I have the clutch fork that came with the 5 speed. So it seems to me that I have all the correct parts this time around.

 

The first time I did the instal I unknowingly used the 200mm TO collar and the bearing for new 225mm clutch kit. That didn't work.

 

The second time I attempted the install I used a 240mm TO collar with the bearing that came with it. It was a little thinner than the bearing that came with the clutch kit, but I didn't have a press to swap them. I did this because of the two 225mm TO collars Mike sent me it was very close to the short one, which is used on '71-'74 clutches.

 

Everything should work this time because now I have the right info and parts.

 

The transmission bolts into the truck with no problem so I'm not worried about that.

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:thumbup:

 

Gear........F4W63.... % change.........FS5W71B.... % change

 

1st.......... 3.657............................... 3.321

2nd......... 2.177..... 42..................... 2.077........... 37.5

3rd.......... 1.419..... 33.....................1.308............ 37.0

4th.......... 1.000..... 30......................1.000........... 23.5

5th................................................... 0.864........... 13.6

 

 

I found my old 521 (same gears as your old four speed) just screamed through first gear by the cross walk on the other side of an intersection. It was ready to shift in two truck lengths. Taking off in second was just a little too high. I found first a waste unless carrying a load or off road on a hill.

 

For around town you may find the new first a nice compromise.

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Who would have thought centimetres would make that much of a difference. Whoops.

 

Now I need a longer speedo cable because the speedo drive is not only furthar back on the 5 speed but also on the opposite side of the truck.

 

Any PN? I'm guessing a '75 620?

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I had a short 4 speed like your old one and was able to swap a zx 5 speed in and use the cable farther back and on the other side. The old one is held to the body or frame by little clips. Unhook all of them to get the cable pulled up into the engine compartment, then run it down the back of the head over top of the transmission and it should reach.

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Who would have thought centimetres would make that much of a difference. Whoops.

 

Now I need a longer speedo cable because the speedo drive is not only furthar back on the 5 speed but also on the opposite side of the truck.

 

Any PN? I'm guessing a '75 620?

If you need a cable extension, Trail-Gear makes one for the Toyotas which I believe is the same thread.

 

https://www.trail-gear.com/TG/Speedometer_Extension_Cable/i_0_0_795/_100063-1-KIT.aspx#.VW3cnVIl-5I

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Hey yeah so its in and working....

 

i have a bad exhaust leak cause the exhaust is touching the transmission and so it rattles alot. thanks for all the help and especially those dimension charts. 

 

any time you wanna come up and hang out scooter just pm and let me know!

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How's it feel to have that 5 speed??? Shift alright? Quiet? First is a little different but less shifting in the middle of intersections. Damn, so glad you got that bitch in.

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