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[1991civicsi]

After changing the bearings and seals on my SOHC trans, I followed the Helm manual to measure for the mainshaft shim.

Helm instructions are to take two seperate readings and follow the formula:
B + C - 0.95 = shim thickness.

To determine factor "B" in the equation, the following must be installed onto the mainshaft as shown in my pic.
Thrust washer
3rd/4th Synchro Hub
Spacer Collar
5th Synchro Hub
Bearing


After the shim and oil guide plate are removed, the shaft is installed back into the housing.


A measurement is taken from the housing and the thrust washer.


The distance for "B" is Zero


The next factor is "C", and this is what we need to measure:


The measurement for "C" is 1.11mm



So the formula is A+B-0.95=shim size, right?

0 + 1.11 - 0.95 = 0.16mm

The only problem is there is no shim size less the 0.60mm.

I have no idea what I am doing wrong. If you have any suggestions I would appreciate hearing them. TIA

[crttaz]

if you only changed the bearings, no need to reshim.

Besides after doing all that you still need to spend about $250 on tools to measure the preload on the mainshaft.

I haven't spent that money, but know of a short cut.

[1991civicsi]

   Bone thank you for your input, I appreciate all the help so far.
 
  I have one simple question. The shim that was installed from the factory is 1.00mm.
 
 Why is it that the Helm manual calls for a 0.16mm shim when I use the formula
 (B+C-0.95= shim size).
 
ATM Im looking into a OEM mainshaft holder with the collar and base, or at least fabricating one to get an exact reading.

[danz]

the good ol bone case pop feeler trick.

[1991civicsi]

the good ol bone case pop feeler trick.

Why am I always the last one to find out? 

[crttaz]

I once did the shimming per FSM, it SUCKS!!!!!

I then started measuring cases as they came apart for ISB replacements and when the outer case was put back one.

Per FSM you want .004-.007" "pull" on the mainshaft before it bottoms out as checked using the FSM and special tools.

Goin' by at the rate of four to the seventh power, I put two an' two together, Added twelve, an' carried five, Come up with twenty two thousand telephone poles an hour

If you measure the thrust washer height and then thickness, you see just how much room is can collapse. Simple math and you find out that the washer needs .008-.010" preload to still have .004-.007" left before bottoming out.

So....with just the full mainshaft in the cases, it aim for .008-.010" case gap, same feeler gauges I use for setting valve lash on SOHC's.

Sorta like driving the train in reverse!

[crttaz]

I also see where you fucked up, you didn't follow the directions, fucking newbs!!!!!!

To determine factor "B" in the equation, the following must be installed onto the mainshaft as shown in my pic.
Thrust washer
3rd/4th Synchro Hub
Spacer Collar
5th Synchro Hub
Bearing

A measurement is taken from the housing and the thrust washer.

You left the 1.0mm spacer washer in there, only need the thrust washer, not both of them.

[1991civicsi]

I am installing only one washer, the thrust washer (left in pic), not the spring washer.



I just remembered that when I disassembled the trans, there was no thrust washer. Only the spring washer was installed. That is most likely why I am having this obstacle. 
 
 Have you ever seen Honda omit using the thrust washer, or have you ever seen Honda omit the shim altogether?

[1991civicsi]

I had a spare trans, so I went ahead and did the same measurements.


The same parts were installed on the mainshaft.



Then once measured I got a reading of 0.381mm



On the other side of the case I got a reading of 1.98mm

I did the math and this is the conclusion:

A+B - 0.95mm = shim size (On this trans Honda installed a 1.36mm shim)

1.98 + 0.38 = 2.36mm - 0.95 = 1.41mm


Honda installed a 1.36mm shim. This is pretty close to the figure I ended up with.

 

[1991civicsi]

I then started measuring cases as they came apart for ISB replacements and when the outer case was put back one.

Per FSM you want .004-.007" "pull" on the mainshaft before it bottoms out as checked using the FSM and special tools.

If you measure the thrust washer height and then thickness, you see just how much room is can collapse. Simple math and you find out that the washer needs .008-.010" preload to still have .004-.007" left before bottoming out.

So....with just the full mainshaft in the cases, it aim for .008-.010" case gap, same feeler gauges I use for setting valve lash on SOHC's.

     I aim for .008-.010" case gap with just the mainshaft and washers properly installed.

My math, the spring washer is .030" thick material, but .046" tall, meaning it has .016" to crush.

.016" - .010" case gap = .006" left as would be measured with correct tools that Aquafina uses.

I understand the principle. The spring washer will only collapse so much, but, where exactly are you putting the feeler gauge if both of the halves of the trans case are together? A pic is worth a thousand words.



This is a pic of what the spare mainshaft looks like in the case I am rebuilding. There is no gap. It could be possible the case is defective.

[1991civicsi]

I was just informed that 1989 trans do not use thrust washer, only spring washer.
DOH!

[crttaz]

I was just informed that 1989 trans do not use thrust washer, only spring washer.
DOH!

spring washer = thrust washer

88-89 doesn't use spacer washer.

The feeler gauges measure the gap between the cases.

[1991civicsi]

Thanks again Bone I owe you one.

[danz]

get him a young red haired pro

[1991civicsi]

Ok now before I put the trans back together I want to verify the FD. It should be 4.25 but I'll count the teeth on the ring gear and compare the count to the amount of teeth to the small bearing case ring gear teeth.
I searched but could not find out how many teeth are on the Si ring gear. If you know off hand lmk plz. Thanks
I gotta say that this was my first trans rebuild and I am glad I took on the task. I appreciate all the input and threads you guys have made.

[crttaz]

68/16

[crttaz]

get him a young red haired pro

Liz would be nice

[1991civicsi]