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FWD Trans Just Lost 5th Gear

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mnetwork

15+ Year Contributor
1,017
2
Feb 25, 2006
New Milford, New_Jersey
I was fine tuning the car tonight with long 4th gear pulls to red line. I had just finished a pull, pulled over to tweak the map, and started slowly driving off. As I was driving I heard grinding. It sounded much like my bumper was grinding on the ground or on my tire. I pulled over within five seconds of hearing it. I didn't see anything. Started driving and didn't hear the noise for a minute. A minute later the noise comes back and the shifter just pops out of 5th gear. I tried to put it into 5th and it violently pops back out. I drove home slowly in 4th (only 2 miles or so). I pull into the drive way and notice that trans fluid is leaking out of the end cover where 5th gear is. When I looked closely there was an indent between the size of a nickel and a quarter where the fluid was coming out. I don't know how this trans went like this because all this trans pretty much sees is highway pulls, I never launch it from a stop. I'm not sure when I'm going to have the chance to pull the trans and I was wondering what this could be...
 
could of seized fith gear to the counter shaft and so much force on the gear that it came off the shaft and now it just grinds just a thougt.
 
could of seized fith gear to the counter shaft and so much force on the gear that it came off the shaft and now it just grinds just a thougt.

I wonder if I should pull the end cover on the trans first to see if I could just change the gear and cover? I don't have too much knowledge on transmissions.
 
Well, that would be the best place to start.

Tim Zimmer via Evo Phone
 
Same thing happened to my AWD trans. The bearing commited suicide.

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If that's the case you're probably going to want to go through the whole transmission. I found rollers from the bearing everywhere. I knew mine was going out because it was pretty noisy but didn't have another dd at the time to take care of it.
 
Well, that would be the best place to start.

Tim Zimmer via Evo Phone

If something happened to 5th gear, would it be POSSIBLE that the cover could be welded/replaced and that 5th gear coudl be replaced without pulling the trans? The rest of the transmission was driving and shifting perfectly all the way home.
 
Yes the last cover can come off and be replaced with another cover. TRE might have an end cover to replace it. All of 5th gear can be worked on without tearing the case all the way down.
 
Iirc, there was an issue with a nut backing off and causing 5th gear to eat the case, I bet that is what you will find has happened.

After looking at pictures of how the gear is held on and the location, I would be inclined to agree with you. I would be very happy if that's all it was.

Yes the last cover can come off and be replaced with another cover. TRE might have an end cover to replace it. All of 5th gear can be worked on without tearing the case all the way down.

That would be great. I'll either pull the cover today or tomorrow and know for sure what is going on.
 
Be careful when you pull that last cover. The bolts that hold the rear cover down also hold the middle cover down. Not a huge deal but its something you should know.
 
Pulled the car in the garage and pulled the end cover. It seems to be exactly what was suggested before, it looks as if the nut backed off of the smaller gear causing all this. Here are the pics...

Here is the indent where the nut cut into the cover...
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Here is the inside of the cover where the nut cut into it along with a broken tooth from the gear...
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Here is the other side of the inside of the cover and some sort of washer/bushing type thing (I made it stand up to show it's form)...
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The smaller gear all chewed up...
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The larger gear all chewed up and missing a tooth...
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Ok, so now I have to put a list together of what to buy so I can fix this. What do I need to buy? I already know I need that nut, the 5th gear set (which includes both the small and large gear I assume), of course fluid... I'm not sure what that small bushing is in the 3rd picture. Also, could I just have this cover welded rather than buy a new one?
 
well, i don't have a complete list of what you need, but i can say that yes, that cover can be welded. I've fixed a lot of DSM tranny cases, welded up everything from holes from exploded diff's to the same exact 5th gear issue. You'll be fine taking it to most welding shops, but it will take several passes and grindings before you get a good final pass/bead on it, the DSM castings are Der-tay (= dirty and then some LOL )
 
Before purchasing anything, I would recommend that you open up the transmission further if it is currently off the vehicle as you have gear teeth damage to your 5th assembly, the debris may have damaged other things in your transmission. I would strongly recommend a complete teardown, inspection and cleaning before going further.

If you prefer to only repair the 5th gearset, end shaft nuts, reverse wave spring, reverse cone, shift fork roll pin, and 5th gear cover, then here is a list of parts below for your 2G FWD Transmission:

MD742040 - FWD 5th Gear - $189.43
MD740767 - FWD 5th Intermediate Gear - $72.48
MD731948 - End Shaft Nut (x2) - $11.16
MD744342 - Reverse Wave Spring - $4.66
MD725928 - Reverse Cone - $24.12
MD736513 - Reverse Cone Machine Screws (x3) - $2.52
MD701722 - Shift Fork Roll Pin - $0.82
MD742106 - 5th Gear Cover - $31.34
MF472402 - 5th Gear Cover Case Dowels (x2) - $2.16

These are approximate prices; prices may vary. Use for reference only.
 
well, i don't have a complete list of what you need, but i can say that yes, that cover can be welded. I've fixed a lot of DSM tranny cases, welded up everything from holes from exploded diff's to the same exact 5th gear issue. You'll be fine taking it to most welding shops, but it will take several passes and grindings before you get a good final pass/bead on it, the DSM castings are Der-tay (= dirty and then some LOL )

After seeing the price of a cover, I'd rather just buy a new cover. I would probably get charged the same just to repair it. I don't weld and I'm not sure if any of my friends weld aluminum.

Before purchasing anything, I would recommend that you open up the transmission further if it is currently off the vehicle as you have gear teeth damage to your 5th assembly, the debris may have damaged other things in your transmission. I would strongly recommend a complete teardown, inspection and cleaning before going further.

If you prefer to only repair the 5th gearset, end shaft nuts, reverse wave spring, reverse cone, shift fork roll pin, and 5th gear cover, then here is a list of parts below for your 2G FWD Transmission:

MD742040 - FWD 5th Gear - $189.43
MD740767 - FWD 5th Intermediate Gear - $72.48
MD731948 - End Shaft Nut (x2) - $11.16
MD744342 - Reverse Wave Spring - $4.66
MD725928 - Reverse Cone - $24.12
MD736513 - Reverse Cone Machine Screws (x3) - $2.52
MD701722 - Shift Fork Roll Pin - $0.82
MD742106 - 5th Gear Cover - $31.34
MF472402 - 5th Gear Cover Case Dowels (x2) - $2.16

These are approximate prices; prices may vary. Use for reference only.

I know these aren't set prices, but the 5th gear set here adds up to $261.91. Jack's lists the EVOIII 5th gearset for $221.45. Are they usually the same price or is one a little more? If I have to buy new gears and they are close in price, I may just buy the EVOIII gear set.

Also, how exactly dose the reverse cone work and why do you think I need one? From what I saw, it didn't look damaged, but I'm not sure exactly how it works. Also, I assumed that he wave spring was damaged because of it's shape, but now that I see it's name (wave) I assume it is supposed to have that shape.

Shift Fork Roll Pin, is that the little pin that sticks in at the base of the fork? Do you just pull this out with pliers?
 
After seeing the price of a cover, I'd rather just buy a new cover. I would probably get charged the same just to repair it. I don't weld and I'm not sure if any of my friends weld aluminum.



I know these aren't set prices, but the 5th gear set here adds up to $261.91. Jack's lists the EVOIII 5th gearset for $221.45. Are they usually the same price or is one a little more? If I have to buy new gears and they are close in price, I may just buy the EVOIII gear set.

Also, how exactly dose the reverse cone work and why do you think I need one? From what I saw, it didn't look damaged, but I'm not sure exactly how it works. Also, I assumed that he wave spring was damaged because of it's shape, but now that I see it's name (wave) I assume it is supposed to have that shape.

Shift Fork Roll Pin, is that the little pin that sticks in at the base of the fork? Do you just pull this out with pliers?

If you want an Evo 3 5th gearset, fine. The gearset would be ~17% taller than your current one. I was giving you the proper OEM part numbers for your application being a FWD. As for pricing, no, they are not always the same whatsoever; it is what it is.

The reverse cone puts pressure on the reverse synchro when the 5th/Rev hub and slider actuates reverse gear while the reverse wave spring keeps pressure on the synchro so when the slider is disengaged, the synchro moves away from the reverse cone under spring pressure. The wave spring should have two locking tabs to retain it in place on the machined indent on the reverse cone.

The 5th/rev shift fork roll pin requires a 3/16" diameter roll pin punch and a hammer to remove. Actuate the transmission into reverse, while holding pressure on the reverse synchro with your hand. Then with it engaged in reverse, use the roll pin punch and hammer to remove the shift fork roll pin.
 
I just destroyed my transmission and it almost seems cheaper to get a used one and drop it in. Since you have a FWD like myself and wheel hop destroys our trannys the inside of your case could be just as bad. If you have a F5M33 transmission I could part with my cover since my transmission is destroyed:beatentodeath::banghead:
 
If you want an Evo 3 5th gearset, fine. The gearset would be ~17% taller than your current one. I was giving you the proper OEM part numbers for your application being a FWD. As for pricing, no, they are not always the same whatsoever; it is what it is.

The reverse cone puts pressure on the reverse synchro when the 5th/Rev hub and slider actuates reverse gear while the reverse wave spring keeps pressure on the synchro so when the slider is disengaged, the synchro moves away from the reverse cone under spring pressure. The wave spring should have two locking tabs to retain it in place on the machined indent on the reverse cone.

The 5th/rev shift fork roll pin requires a 3/16" diameter roll pin punch and a hammer to remove. Actuate the transmission into reverse, while holding pressure on the reverse synchro with your hand. Then with it engaged in reverse, use the roll pin punch and hammer to remove the shift fork roll pin.

That sounds easy enough. Is there a specific reason why I would need a new reverse cone?
 
Well, you have an end shaft nut that backed off, and a 5th assembly that is wrecked. Why don't you look at the reverse cone, inspect it for wear or damage, and replace it if necessary.

I was simply giving you the correct part numbers to fix your car. It is your choice what you want to pay for.
 
Well, you have an end shaft nut that backed off, and a 5th assembly that is wrecked. Why don't you look at the reverse cone, inspect it for wear or damage, and replace it if necessary.

I was simply giving you the correct part numbers to fix your car. It is your choice what you want to pay for.

I didn't know if you saw something specific in the pictures. I will take a close look and report back.

I didn't know if you saw something specific in the pictures. I will take a close look and report back.

I just checked and the reverse cone is definatley fine. My concern now is getting the roll pin out. You say I have to put it in reverse and put pressure on the reverse syncro? When I put pressure on the syncro, this will give me the clearance needed to pull the pin out?

Also, I have sent you a pm.
 
I will be following this closely because I might decide to tear into the end of my trans to install an evoIII 5th one of these days.

I have already listed several times in posts how to do a full teardown for FWD and AWD transmissions for various reasons such as shift fork replacement, input shaft seal replacement, output shaft replacement, etc. You would only need the first few steps to do a 5th gear assembly swap.

http://www.dsmtuners.com/forums/152394201-post20.html
Here is just one of several posts on this forum regarding transmission teardown.

If you do an advanced search for my user name you will find many more by using key words like "F5M33", "W5M33", "rebuild", "remove", "seal", "shift fork", etc.
 
I have already listed several times in posts how to do a full teardown for FWD and AWD transmissions for various reasons such as shift fork replacement, input shaft seal replacement, output shaft replacement, etc. You would only need the first few steps to do a 5th gear assembly swap.

http://www.dsmtuners.com/forums/152394201-post20.html
Here is just one of several posts on this forum regarding transmission teardown.

If you do an advanced search for my user name you will find many more by using key words like "F5M33", "W5M33", "rebuild", "remove", "seal", "shift fork", etc.

I'm still a little confused on how you remove the roll pin? Are you supposed to push it outward or inward?

If inward, how? Because it seems like it would hit the syncros.

If outward, how do you get a punch behind it with the syncros in the way?
 
I'm still a little confused on how you remove the roll pin? Are you supposed to push it outward or inward?

If inward, how? Because it seems like it would hit the syncros.

If outward, how do you get a punch behind it with the syncros in the way?

There are several years and models that the pin can simply be punched inwards and it clears no problem, while there are several that either require a bit of fanaggling directing the roll pin towards the hub and slider keyway while rotating the assembly to work it out. Otherwise, you punch it outwards by either using a 1/8" roll pin punch and curve out the pin. You can then direct it out with a 1/8" or 3/16" pin punch.

If you get it started enough where you can get a vise-grips on the roll pin, then you simply lever it with a prybar between the shift fork and the visegrips.
 
There are several years and models that the pin can simply be punched inwards and it clears no problem, while there are several that either require a bit of fanaggling directing the roll pin towards the hub and slider keyway while rotating the assembly to work it out. Otherwise, you punch it outwards by either using a 1/8" roll pin punch and curve out the pin. You can then direct it out with a 1/8" or 3/16" pin punch.

If you get it started enough where you can get a vise-grips on the roll pin, then you simply lever it with a prybar between the shift fork and the visegrips.

Spent about an hour trying to get the roll pin out without breaking anything. I don't know how to get that out (with the trans still in the car) correctly. I could only do it from outside to inside, because there is no room to do anything else. The roll pin did run into the slider. I had to dremel as much as I could of the roll pin and then hammer it so it would bend out of the way. At that point I was able to punch the roll pin out the rest of the way.

When I buy the new gears, I'm just trying to remember how everything goes back together.

I took the two springs that hold the three metal pieces on the slider gear out. Do those go in a certain orientation?

Which syncro goes where?

Which way does the slider gear go on top of 5th gear (up/down?)?
 
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