930 1st Engine Drop & Trans R&R

[paganrj]

Mike,
Just noticed that you are dealing with the same job I am at this moment. One issue that I had during the first rebuilt was replacing the big 36mm nut. I could not locate one anywhere so ended up reusing the old one. I will like to replace it now but still no word on where to find it. If find it available anywhere (or anybody else know where to get it from) please post it here. I am sure there are some others looking for it too.
Regards,
Rey

[MikeD930]

Rey, I'm sure you can find the 36mm nut here at Pelicanparts. If they are out then I think Stoddard carries them. I will be replacing new 30mm & 36mm nuts. The ones I removed were obviously re-used so I'd rather ditch them (not sure if it's okay to re-use more than once).

[MikeD930]

I just took apart 4th gear revealing its innards.

Removed lock washer




Removed bands, stop and lock




Removed syncro ring




I'm glad to find that the bands, stop and lock for 4th gear are in great shape. I'll be taking apart the other three gears tomorrow.

[Chinook]

Really good stuff Mike. Thanks for the photo/ sharing effort. How do you plan to reconcile the 1-2 fork misalignment?

Gary

[paganrj]

Originally Posted by MikeD94

Rey, I'm sure you can find the 36mm nut here at Pelicanparts. If they are out then I think Stoddard carries them. I will be replacing new 30mm & 36mm nuts. The ones I removed were obviously re-used so I'd rather ditch them (not sure if it's okay to re-use more than once).

The 30mm nut can be found easily, PP has it for $14.50. Is the 36mm (930-302-453.00) the one that me an others have not been able to find. The host has NLA on it.

[Matt Monson]

I've got that nut...

[paganrj]

Originally Posted by Chinook

Really good stuff Mike. Thanks for the photo/ sharing effort. How do you plan to reconcile the 1-2 fork misalignment?

Gary

In order to adjust shift forks, the main shaft and pinion shaft nuts must be tightened to their actual torque spec.This will draw all the components of the gear stack together as they will be in the finished transmission using a special shift fork jig like in the pictures/procedure below

[MikeD930]

Here are 1st, 2nd & 3rd gear innards beginning with 3rd gear.

Removed lock washer (3rd gear)




Removed bands, stop and lock (3rd gear)




Removed syncro ring (3rd gear)




Removed lock washer (2nd gear)




Removed bands, stop and lock (2nd gear)




Removed syncro ring (2nd gear)




Removed lock washer (1st gear)




Removed bands, stop and lock (1st gear)




Removed syncro ring (1st gear)




All bands, stop and lock looks good.

continue...

[MikeD930]

Now lets take a look at the shift forks.

1st/2nd gear fork





Both sides looks good.

But here's the strange part. See closeup photo below. Note that the shift fork pinch bolt is "bottomed out" against the notch. As mentioned in earlier post the 1st/2nd gear slider was not centered (too close to 1st gear). For some reason whoever worked on this gearbox (replaced stock 2nd-4th gears with shorter gears) did not set up this fork properly. I suspect that the mechanic did not install reverse gears and tightened the shaft nuts to close up the gear cluster when checking the forks or was just too lazy to center the slider.




3rd/4th gear fork





Both sides looks good.


Note that pinch bolt is not against the notch. It's more centered within the notch.




Now I'm off to look for taller 2nd, 3rd & 4th gears and put together a list of parts needed for this rebuild. I just ordered a Kevlar disc (with springs) from Clutchnet and also called KEP to ask about rebuilding the PP (Chris @ TurboKraft, thanks for the suggestion!). They said no problem and turn around time is about a week from time of receiving the PP. I asked about which version of PP I have. They said it can be determined by measuring the thickness of the diaphragm. Stage 1 is .137" thick and Stage 2 is .145" thick. Mine measures .138 so it's a Stage 1. I think I'll stay with Stage 1 using Kevlar disc. It held up well with 444 rwhp and I have no short term plan to increase HP.

[MikeD930]

Originally Posted by Matt Monson

I've got that nut...

Hello Matt...I hope you have a few laying around. Are these NLA or did you have them made?

[jwasbury]

Mike,

Great job on this, and great photos/documentation/explanation. I have some issues with the 915 from my race car that need sorting before she goes on the track next season. I am debating tackling it myself, so your journey provides some inspiration and motivation for me.

AND

It's nice to see some more DIY at the top of the forum posts.

[Miguel Antonett]

^^^+1 Tpalloza boys!!!

[infraredcalvin]

Be careful when using the SIR tool to remove the dog teeth. The ridge on the tool is backwards compared to how it should fit. I had particular trouble with first gear dogs and busted up the $100 tool on the first try. Was told later to use a hammer on the tool,instead of a press... More info can be provided if anyone wants it...

[MikeD930]

Jacob...thanks. Agree that there should be more DIY around here. I never tire of learning from others.

Miguel...TP'looza...yeah!

Pat...please do provide more information right here (or start a new thread if it's long) about what you went thru with SIR tools removing the syncro hubs/teeth.

[Matt Monson]

Originally Posted by MikeD94

Hello Matt...I hope you have a few laying around. Are these NLA or did you have them made?

NLA. These are NOS. I have 5.

[boosted79]

Mike - Great write up. Any idea on how many miles on the box?

[MikeD930]

^^^about 37k miles (20k miles with shorter gears) on the box.

[MikeD930]

It's been a while since my last update. I found several sources for custom gear sets. Originally my plan was to go with stock 1st gear, 1.444 2nd gear, .963 3rd and .688 4th. But I would have to buy new 3rd & 4th gear sets which were out of my price range. So I had to compromise with whatever used gear sets were available. First I found .656 4th gear set which I had to return due to its bearing surfaces being fretted (had some pittings from corrosion) in spite of its seller claiming "excellent" condition. Yeah right...got my money back. I ended up with 1.444 2nd, .928 3rd and .625 4th (stock) gear sets. The synchro hubs on 3rd and 4th gear sets are in excellent condition so I won't be replacing those. I replaced the synchro hubs on 1st and 2nd gear sets. Here's how I accomplished this.

A sharp chisel is used between the synchro teeth and flat surface of gear shown below (1.60 gear shown as a demonstration). I worked the chisel around the gear slowly lifting the synchro hub up away from the face of a gear. This process took about 10 min and I wore safety glasses during this procedure.






Before installing a new synchro hub I added slight chamfers to the splines on the gear using a dremel tool to make it easier to get the synchro hub started. Then I heated up the synchro slowly going around the entire synchro hub repeatedly using a propane torch to around 200 deg F. I used a infrared heat sensor gun to check its temperature.




Then I installed the synchro hub onto the gear using a 2 3/4" dia pipe, 2x4 and hammer as shown below.








I will have a machine shop to verify the I.D. of the bearing surfaces to check for any variation of its diameter due to installed new synchro hubs. Any variations will be honed out. But 2nd gear will need to be cleaned up anyway since there is a dimple at the end of the bearing surface which was already present when I received this gear from the seller (see below). The seller agreed to refund a portion of his sale to pay for this cleanup. Also, another challenge with 2nd gear was that its synchro hub was tacked (brazed) onto the gear. I was able to carefully remove the brazing using a dremel tool with small thin grinding wheel (again wore safety glasses!) before removing the synchro hub.






On another note I had my KEP stage 1 pressure plate rebuilt by KEP. It turned out like new! This PP turned out to be custom setup using G50 PP with 930 diaphragm spring plate (to accommodate G50 flywheel which is used with Protomotive Motronic EFI).






The flywheel will be cleaned up and resurfaced at a machine shop who will also work on the gears.

[MikeD930]

I'd thought I'd share my study on the gearing versus my car's dyno hp/torque curve. The dyno was done by a PO back in 2004 and there were no further changes on the engine/turbo. So its hp/torque curve is still valid. Below is a dyno chart and I'm not sure why the dyno run was shut down at 6k rpm instead of 7k. HP was still climbing when it was shut down. So I'll have to assume that hp drops shortly after 6.5k rpm when working with thrust calculation.

Although my car had short 2nd, 3rd & 4th gears (1.60, 1.12 & .792) which was awesome but
my goal is to have tall 4th gear for relatively low rpm cruising on highway while first three gears will close enough for spirit driving. After calculating the thrust of each gear I've determined that I'll be able to stay in the powerband with wider gear ratios between 2nd, 3rd & 4th gears while closing up wide gap between stock 1st-2nd gears.

Here's the dyno chart




Below is a thrust (lbs vs. speed) chart with color coded for different gearing ratios. You can see that the previous short gearing results in impressive thrust in every gears. This shows why one would set up gearing for certain tracks or known planned top speed. It's too bad I could not just add 5th tall gear without resorting to a Ruf 5sp or G50 gearbox.

[Alan L]

Mike you are doing a great job. I see you have a w/shop manual also. If you do get stuck you can search for an excellent link on this forum 'Can't shift into first' - pics and blow by blow description.
From memory, when I did my 930 box I had to make a long socket tool to get at a nut on a shaft. I split the socket thru the diameter, and welded each bit on opposite ends of a pipe - if that helps.
Regards
Alan