Tranny stuck in 3rd. couple questons

[91DSMdave]

Ok. So i have a 90 laser fwd, and i need to fix my tranny. It IS a 90 tranny. i was driving, and went to pass someone. Went from 3rd to 2nd, back to 3rd, and into 4th. Came to a stop down the road a bit, went out of 4th into 1st, and the car wouldn't move, like the trans was binding up. For example if i was to rev it up and drop the clutch, it would sit in one spot, smoking the clutch. From what i have researched, i think my 3rd gear shift fork is broke.

I have a 91-94 tranny that is good, other than the throwout bearing sleeve which broke off the bellhousing. my question is, can i take parts out of the 91-94 and put them in the 90? Or take the bellhousing off of the 90 and put it on the 91-94?

And where could i find the gaskets i need?

 

[dented_coffee]

RTV form-a-gasket will be your best friend there. Just put a nice bead on there and place the 2 parts together eveny (dont smush them together completely and dont tighten the bolts down yet). Let it get nice and tacky then tighten it to spec. it avoids getting big globs all over in the trans and avoids having leaks.

As for the trans. If I remember correctly the gears are differnet in the 90's. The bell housing should bolt right onto the 91 trans. But you will need to change your shifter cables and shifter assembly to use that trans in your DSM. I think your gonna have to change your CV shafts as well. I think the spline count on the shafts are different than the 91 and up.

If I were you I would tear the trans down because it's broke anyway so whats the worse you can do really. Take it appart and inspect it all. If its a broken fork and not just a bent fork inspect each gear and tooth for any damage. If it all checks fins clean it all out and repace the bad part, lube everything as you put it in and get it back in your DSM for a test run. Call any trans rebuilding shop or OEM retailer and they can get you the parts you need. A trans shop might even be able to give you some pointers on rebuilding the trans as well.

One last thing. While your inside the trans I would replace the syncros while its appart. It will shift alot better and be easyr on the trans as well with fresh syncros instaled.

 

[domthebomb11208]

90 gears are different. Your best best is to get that one rebuilt. Or switch to the 91 and up style. If you need either one rebuilt shoot me a pm.

Thanks.

 

[1g_brandon]

If it is just the 3rd gear fork then pull it from the other trans and put it on. once put back together turn input shaft and switch through gears to insure trans is operating correctly before reinstalling.

 

[domthebomb11208]

If it is just the 3rd gear fork then pull it from the other trans and put it on. once put back together turn input shaft and switch through gears to insure trans is operating correctly before reinstalling.

if they are the same....

92 1/2 and up had a different 3-4 shift fork

 

[Auto RS T]

Full rebuild just for a fork??? ...c'mon now...

Get the fork and put it in, or get yourself another 90 trans to break.

 

[domthebomb11208]

Full rebuild just for a fork??? ...c'mon now...

Get the fork and put it in, or get yourself another 90 trans to break.

Not all dsmer's know how to change a fork...or they are scared to pull a dsm trans apart in general.

Plus we double pin our forks with our builds to help elimate forks breaking.

 

[AWD-TSI]

My trans broke on me last night. It locked itself in first, I managed to get it out. Now it wont go into first. Fifth and reverse are very difficult to go into as well. sorry for high jacking the thread.

 

[twicks69]

My trans broke on me last night. It locked itself in first, I managed to get it out. Now it wont go into first. Fifth and reverse are very difficult to go into as well. sorry for high jacking the thread.

You will be requiring a rebuild. As well, your post is a statement -- are you looking for advice or something?



I am sorry that I didn't see this thread until today. If you have fixed your problem, cool! Otherwise, if you haven't, here is a quick rundown of how to do it yourself.

As for the original poster, 91DSMDave - If it is a simple shift fork, do yourself a favor, and download the transmission service manual for your trans -- F5M33 --
http://www.3sx.com/faq/manuals/Service-Manual-Transmission-FWD-Mitsubishi-Manual.pdf

Then, get the tools required for the job, and do a shift fork yourself. The F5M33 transmission is a snap to work on, and only takes a couple minutes to do a shift fork replacement.

Remove the 5th gear cover, 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. With 1990-early 1991 transmissions, there is a small diameter 5th/Reverse hub/slider/synchronizer assembly whereas the late 1991-1994 have a large diameter 5th/Reverse hub/slider/synchronizer assembly. 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. If you intend on swapping the 5th/Reverse assembly for the large diameter unit, be sure to swap the 5th gear cover and shift fork as well.

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. 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.

Remove output shaft. Remove/clean/inspect output shaft and front differential.

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.

Remove broken shift fork. Replace shift fork. Inspect entire assembly and clean transmission case and magnet of any debris.

With new 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 broken shift fork or inspection/disassembly of a F5M33 FWD turbo 5-speed transmission for a 4G63 FWD turbo DSM 1991-1999. It is nearly the same disassembly for the AWD W5M33 transmission other than the viscous coupler snapring, viscous coupler, viscous coupler detent ball, center differential and intermediate case section.

Non-reusable parts mentioned -

FWD trans:
End Shaft Nut - MD731948 x 2
Roll Pins - MD701722 x 3

AWD trans:
End Shaft Nut - MD731948 x 2
Roll Pins - MD701722 x 3
Viscous coupler snapring - MD720687

1G FWD turbo (F5M33) Shift Forks -
1st/2nd - MD720341
3rd/4th - MD741558 (two rail holes)
5th/Rev - MD735237

1G AWD turbo (W5M33) Shift Forks -
1st/2nd - MD723439
3rd/4th (1989-late 1992 - two rail holes) - MD741558
3rd/4th (late 1992-1994 - three rail holes) - MD746854
5th/Rev (1989- mid 1991 - small diameter synchro) - MD735237
5th/Rev (late 1991-1994 - large diameter synchro) - MD741187

2G FWD turbo (F5M33) Shift Forks -
1st/2nd - MD720341
3rd/4th - MD746854 (three rail holes)
5th/Rev - MD748630

2G AWD turbo (W5M33) Shift Forks -
1st/2nd - MD723439
3rd/4th - MD746854 (three rail holes)
5th/Rev - MD748630


As you can see, there are some parts interchangability between 1G and 2G AWD/FWD transmissions, but they are specifically to certain parts.

As well, you may swap AWD 5th gear components/hub slider/gears/synchros and shift fork into FWD transmission cases that have a reverse synchro and reverse cone installed. OR, you can swap late-model reverse synchro parts into early-model 1989-1990 transmissions to get a reverse synchro/reverse cone assembly installed instead of a lockout plate.

Same thing goes for FWD 5th gear assemblies into AWD cars, the 5th gears, hub and slider assembly, synchros and shift fork must be swapped. If you are swapping from small diameter to large diameter synchro assemblies, the late model 5th gear cover must be swapped also (This is for AWD applications; from what I recall, all 1G FWD turbo transmissions have the same 5th gear end cover).


Good luck with the project!

Tim Zimmer
TMZ Performance