Late 5 speed roll pin replacement

Author: sweething_2_5 of zcar.com


I finally got around today, to replacing the roll pin for my 3rd and 4th gear fork. I pulled the tranny and whatnot today, and i took some pics in order to give others an idea of how to go about this. You know it is the pins in the forks when you put it in gear and nothing happens, both my 3rd and forth gears wouldnt do anything but it would go into gear.
The 1st, 2nd,3rd, 4th forks are all in the front part of the tranny, where the bellhousing is, 5th and reverse are in the back part. All you need to take apart is the front section, but for some reason mine wouldnt come apart so i ended up taking the entire trans apart. Wasnt to bad, i just followed the fsm for most of the tear down and reassembly. Meke sure to empty all oil before taking the thing apart.



Ready to be torn apart:


Front cover removed in the bellhousing:


Front cover part and bolts...


Clips to remove:


Transmission case apart:


The different pins in the trans:


The replacement pin, i actually put another smaller pin inside this one to add strength:

 

 

Author: GrahamBCZ 
Date:   Feb 5, 2002 10:40am



Here are some tips on areas that are a bit tricky when building a 5 speed. You should have a manual with some decent pictures or diagrams before you attempt to do one. There are too many ways to screw up without at least minimal reference material.


Figure (1) In order to get the extension housing off you have to disengage the selector rod from the fork rods. Once the bolts holding the extension housing are removed, remove the speedo bullet and driven gear. Then remove the clevis pin and ďEíí clip (B) and the reverse spring and cup (A) seen in figure 5.

As you lift the extension housing off, you will have to pry it open at first, the selector rod will hang up on the shift forks (see figure 1) The selector rod (A) has to be rotated so the tab (C) disengages the fork rods (B) this is done by putting a screwdriver into the selector rod where the cup at the bottom of the shifter sits. As you lift the housing off the tab (C) on the selector rod (A) will then hang up on the rear bearing of the mainshaft so it will have to be rotated the other way to clear. It takes a bit of fiddling around so be patient!

When reassembling the tranny try and put the extension housing on a few times and engage the rods . You can tell when they are engaged when the rod (A) wonít slide in and out of the tranny at the back. Donít rotate the rod side to side and Put a screw driver in and pry the rod back into 3rd gear and then pry it forward into 4th, it should click into each gear if it is engaged properly. Donít try 1st-2nd or 5th Ėrev.
When you put it back on for real after you have applied the silicone sealer as soon as you have the rods engaged put the clevis pin back in (figure 5 B) this will prevent the rod from rotating out of position which is impossible to re-engage after the housing is bolted down.

Figure (3) There are three interlock balls and springs on the outside of the center support. The long spring is the one on top the 2 short ones go on the side (A) they are a held in with a 14 mm plug. There are interlock balls on the inside as well so when you remove the fork rods be aware of them (B) so they donít fall out and you lose them. Usually 2 balls or a slug between the three rods.

Figure (4)After all the roll pins on the shift forks have been removed, mark the fork rods from top to bottom as you remove them and each fork as well, mark the fork with an arrow pointing forward to the front of the tranny and mark what shaft it came off of. They have to go back in the same spot facing the same direction when reassembling. They will only fit one way for it to work but if you mark everything it will save time second guessing yourself.

Figure (6) If you get like this E mail me!
If you follow the manual you should have no problem, again these are just some examples of stuff that can be a bit vague in the manual. Be patient is the best advice on top of getting a decent manual.
When you get the extension housing and front cover off, clamp the center support in a solid vise. Spend some time checking it out. Move each fork rod to see how the gears engage. Make a mental note of what components are freewheeling on the mainshaft and which are not. In neutral all the gears should rotate freely. The slider hubs are splined to the mainshaft. The speedo worm gear and some of the thrust washers are held with a small ball. Be sure to watch for them as you remove them.
Most Important! I do this for a living and a lot of tthese things I can do in my sleep. I always lay the parts out in order of removal on my bench roughly oriented as to how they would be assembled. I have customers and a Boss who frequently pick up and look at the parts when it is disassembled. You probably have a little brother or wife who wants to clear the table for diner. Also, get all the parts from your dirtbike or your Sus or the washing machine well away from your work area, you donít want to be mixing stuff up.
Never! Sand or wire wheel the friction surface of the gears where the synchros engage. If you are replacing the synchros buy them from the dealer. I have had too many headaches with after market ones, the extra money is worth not having the brain damage. If synchro surfaces of the gears are really shiney Take an old synchro ring that you arenít reusing. Put some valve grinding past on it and press it onto the gear and give it a twist each way, keep doing it until the surface isnít shiney any more. Donít spin it , just press it on and twist, itís time consuming and hard on your hands but worth it. Note: after doing this it is usual for the tranny to be a little difficult to shift at first but once the synchros seat in youíll be amazed at how smooth it will shift. Good luck!
Graham.

 

If you resurface the gears with valve grinding paste be sure to clean them good afterward. You don't want valve grinding paste in the transmission.
In figure (5) The reverse spring cup (A) When re installing the ridge is horizontal and the hole goes down.
The screws holding the bearing retainer plate on the center housing are "torx" T-40 in case you have to go and buy one. When you re-install those screws, stake them or use locktite.
To remove the 38mm nut on the back of the mainshaft. With the center support clamped in a sturdy vise slide the drive shaft onto the back of the shaft. Put a long pry bar through the yoke and get someone to hold it while you undo the nut. Try to pry the collar of the nut out of the locking channel if you can. You can also remove the shift forks and lock the trannsmission in 2 gears so it won't turn but the first method is preferred.


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