1G broken 3/4 shift fork?

[93blueGS]

So my cousin calls me up yesterday and asks me to look at his car and see why its hitting fuel cut.. He picks me up and we go for a ride..

We get to a location where we can get on it so he asks me to drive.. So I get in the driver seat, adjust the seat, and put the clutch in and start moving forward.. Shift into 2nd at 3k rpms and get up to 3k rpms in 2nd and start brake boosting.. Once its builds about 7-8 lbs I lay into it and it starts to spin. Go to shift into 3rd quickly but it hits the rev limiter, so I figured I must have missed third, so I shift to 4th and coast to the stop sign.. Roll to the stop sign with the shifter in neutral and off the clutch pedal.. The car stalls.. So I crank it back up and put it into first.. start to let out the clutch and the car dies automatically without even moving the slightest bit.. Pull the shifter back into neutral and it rolls with the clutch pressed down..

Turns out its stuck in 4th gear right now and Im thinking the 3/4 shift fork broke.. Does that sound right? You can tap the shifter back and forth between 3rd and 4th, but it takes some pressure to get it into 1/2 or 5/R..

I had the same exact problems with my msp a couple years ago when I broke the 3/4 shift fork (ironic)..

Needless to say it never hit fuel cut in my short time of driving it.. so now there are more problems after its said and done..

 

[sniver]

Make sure the cables or linkages are not cocked, undone, or other wise causing the issue. If you don't see anything, see how hard it is to change gear on the trans with the cables off.

 

[93blueGS]

Done all that.. Watched the linkage on the trans as he put it into each gear and it went into each fine..

 

[bastarddsm]

Yep, you broke the shift fork... Do the double roll pin mod and it won't happen again. You'll just break rail ends instead.

 

[twicks69]

Or, you can not shift so hard and stop breaking shift forks.

Either install an Evo 3 3rd/4th steel shift fork, or an OEM aluminum 3rd/4th shift fork with a machined 3rd/4th shift rail for double roll pins.

What year is the transmission/vehicle? I am assuming that it is a 1990-mid 1992 based on the part broken.

 

[93blueGS]

He called me this morning to tell me he somehow got it out of 4th and was able to drive it in 1st, 2nd, 5th and reverse.. But he put it back in 4th once and its stuck again..

Its not like I powershifted it, the part must be really weak..

Its a 92 tsi.. What is the double roll pin mod?

 

[bastarddsm]

He called me this morning to tell me he somehow got it out of 4th and was able to drive it in 1st, 2nd, 5th and reverse.. But he put it back in 4th once and its stuck again..

Its not like I powershifted it, the part must be really weak..

Its a 92 tsi.. What is the double roll pin mod?

It doesn't take much to break it. Just spirited shifting can do it if its old.

basically you drill another hole in the shift rail on the top side of the fork. Its easy to see where it needs to be. You need to take care the pin it tight against the fork.

 

[93blueGS]

Found a 1.8 dsm in the junkyard.. Ive heard that the trans will bolt up.. Is there anything that needs to be changed? We just need this thing going asap as its his DD..

 

[brownfinger]

That trans isn't going to work. You need one for the turbo 2.0. Is it FWD or AWD? That'll matter, too.

 

[bastarddsm]

Stop being a ####y, get the tech manual that is posted on scribed, take that bi*** apart and fix it.

 

[93blueGS]

Stop being a ####y, get the tech manual that is posted on scribed, take that bi*** apart and fix it.

Dont have time to do that right now.. He has to have his car this week.. I wouldnt mind doing it though.. Just need something to get him by until the stock trans gets fixed..

That trans isn't going to work. You need one for the turbo 2.0. Is it FWD or AWD? That'll matter, too.

Go read the paragraph I posted up top.. You'll figure out if its fwd or awd..

 

[twicks69]

Dont have time to do that right now.. He has to have his car this week.. I wouldnt mind doing it though.. Just need something to get him by until the stock trans gets fixed..



Go read the paragraph I posted up top.. You'll figure out if its fwd or awd..

This is like a 30 minute process with the right tools, a couple parts, and a learning experience.

Also, the 1.8 trans is not a bolt-in. The clutch and flywheel are different and won't clear the bellhousing.

As well, assuming things all the time gets tiring. Just state FWD since you didn't directly state it next time.

The OEM 3rd/4th shift fork part number is: MD741558
The Evo 3 3rd/4th steel shift fork part number is: MD749755

The end shaft nuts are: MD731948 x 2
The roll pins are: MD701722 x 3


To do the job, read up:

Remove the 5th gear cover (12mm long and short bolts), manually shift the transmission into reverse (or you can use a roll pin punch and hammer and remove the roll pin from the 5th/Rev shift fork and manually shift the transmission into 1st and 5th) to lock the transmission. Then, using a 1/2" impact and 36mm socket, remove the end shaft nuts from 5th gear and 5th intermediate gear.

If the 5th/Rev shift fork roll pin is still installed, remove it using a 5mm or 3/16" roll pin punch and hammer. It is best to use the pin punch and pound the pin outward as you may get it stuck in the hub assembly if you don't know what you are doing.

Once the hub and slider assembly has been removed, remove the 5th gear and 5th gear split needle bearing. Now, remove the 5th intermediate gear. ***NOTE THE ORIENTATION OF THE 5th intermediate gear and the flange orientation so you don't put it on upside down when reinstalling it.*** It should be easy to remove by hand, or hard to remove requiring special tools -- DO NOT PRY THE GEAR OFF!!! YOU WILL CHIP THE TEETH! Use the proper tool. That would be an OTC 1122 bearing splitter and OTC 7393 push-puller tool by inserting the jaws on the top flange of the 5th intermediate gear and then remove the gear.

Remove the reverse switch (24mm wrench), remove the reverse lockout bolt (19mm), remove the three shift detent poppet plugs (14mm)/springs/detent balls (using a pen magnet), and reverse idler gear bolt (14mm bolt next to front differential passenger-side axle seal).

Remove case section bolts, and remove case section gently using two prybars evenly spreading the case gently upward. ***NOTE THE ORIENTATION OF THE REVERSE IDLER GEAR*** You will need to have the reverse idler shaft oriented properly so that the reverse idler gear shaft bolt properly reinstalls -- note the direction that is required so it matches up with the transmission case for easy installation.

Now, with the case removed, lift up on the reverse idler gear shaft and remove the shaft, then slide out the gear and remove the key from the reverse linkage arm. Remove the two 12mm bolts that attach the reverse linkage arm to the bellhousing. Remove the linkage arm.

(This part is not necessary, but nice to do for inspection purposes)
Remove output shaft. Remove/clean/inspect output shaft and front differential.
(now, back onto the fun...)

Now, using your roll pin punch, remove the roll pins for the 1/2 and 3/4 shift forks. Using your hands or gently using small prybars, orient the 5th/Rev rail end first by pulling upward and away from the shift selector (away from the other two rail ends). While the 5th/Rev rail end is up/away, do the same with the 3/4 rail end so that it clears the shift selector assembly. With the 1st/2nd rail end, go the OPPOSITE DIRECTION and gently move it away from the other two rail ends so that you can slightly modulate the shift selector to clear all three rail ends. Pull up. All the gear clusters and shift rails/rail ends/forks will come up as one single unit.

With the gearset removed, you now have access to the 3rd/4th shift fork. Pull off the shift fork, replace it, fish out the damaged parts that have been bouncing around your transmission. Inspect entire assembly and clean transmission case and magnet of any debris.

With the new shift fork installed, assemble the gear clusters with the shift forks just like how you removed them originally. Reinstall the cluster assembly, modulate the shift rail ends just like how you removed them to get them all back to centered orienation with the 1/2 on the left side of the shift selector, the 3/4 on the center of the shift selector and the 5th/rev on the right side of the shift selector in the neutral position.

Reinstall new roll pins.

Reinstall the reverse linkage arm and 12mm bolts - 16-18 lb/ft torque. Reinstall the reverse linkage key, idler gear and slide the idler gear shaft back into the oiling detent with the bolt hole orientation towards the front diff properly so it aligns with the main case section.

Reinstall the output shaft and front differential.

RTV silicone the case section flange evenly with a thin bead of Permatex Ultra Black or Ultra Gray RTV silicone. Otherwise, using your finger, evenly spread a thin coat on the case section flange so that all contact area is evenly covered with the RTV silicone. Let cure for 15-20 minutes to tack, then install the case section.

Reinstall the case section making sure that you have the magnet tray reinstalled and the black plastic oiling guide reinstalled on the case section.

Reinstall the reverse idler gear bolt to 32-39 lb/ft torque. (Tapered end bolt with aluminum flat washer).

Reinstall the 14mm bolts that attach the main case section to the bellhousing to 29-35 lb/ft torque EVENLY.

Reinstall the 19mm reverse lockout switch bolt (19mm head with spring-loaded detent ball on the end and aluminum flat washer) to 22-25 lb/ft torque.

Reinstall the 24mm reverse switch (plug head with 24mm hex-shape body and aluminum flat washer -- DO NOT FORGET THE WASHER or you will have problems shifting into 5th/Reverse) to 22-25 lb/ft torque.

Reinstall 5th intermediate gear and 5th gear split needle bearings/5th gear. Reinstall the 5th/Reverse hub and slider gently/evenly with 5th and reverse synchros oriented properly so it does not bind up or get damaged. Slide the hub and slider back on WITH THE 5th/Rev shift fork at the same time being installed onto the 5th/Rev rail.

Reinstall the 5th/Rev shift fork roll pin.

Manually shift the transmission into reverse (OR like last time, before reinstalling the roll pin, shift the transmission into 1st manually, then into 5th gear with your hand engaging the hub/slider onto 5th).

Install new end shaft nuts to 102-115 lb/ft torque.

Ping the detents with either a punch/hammer or a small point punch on an air hammer GENTLY for both end shaft nuts.

RTV transmission case flange for 5th gear cover. Let tack 15-20 minutes before reinstallation.

Be sure your reverse wave spring is still in place and reverse synchro is properly reinstalled.

Be sure that you have the roll pin back in the 5th/Rev shift fork, and that the transmission is back in the neutral position.

Reinstall 5th gear cover and 12mm bolts to 16-20 lb/ft torque (FWD cases use this number; AWD cases with 14mm bolts use 26-30 lb/ft torque).

This is a quick rundown of directions for replacement of a 3rd/4th shift fork or inspection/disassembly of a F5M33 FWD turbo 5-speed transmission for a 4G63 FWD turbo DSM 1991-1999.

 

[93blueGS]

Just bought the parts from Jacks..

 

[sniver]

It really is as easy to do as he stated, you won't regret it.

 

[93blueGS]

Ive rebuilt a trans before, but I kept reading about setting preload and shimming the trans.. I wasnt sure what those meant so I wasnt going to attempt it and screw something up..

 

[twicks69]

For replacing a shift fork, you don't need to re-shim a transmission. Normally if it is already within spec you would reshim when replacing bearings and/or checking the preload on the shafts to confirm that it is still within spec.

Just follow the instructions I gave you for a shift fork replacement and it will be a snap.

 

[93blueGS]

Well, got it broken down and more is messed up that previously thought. 4th gear on the intermediate shaft is missing a couple teeth.. fuuuuuuuuu

 

[ist dwa]

First pic is the stock 3/4 fork, 2nd pic is of the extra roll pin hole drilled right in the middle of the fork and shaft with a 3/16" drill bit, real easy IMO.

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