Resolved 1G 2nd & 3rd gear grind before and after rebuild

[Anfurnyy]

Car is a 93 Talon, manual (confirmed to have 93+ trans)
Ever since I got this car in 2020 2nd and 3rd have kind of "clunked"/"grinded" into gear.

Last year I refreshed the trans, replacing all synchros (except 5th/reverse), new keys, springs, 1/2 and 3/4 shift forks, new bearings, cleaned out the input and intermediate shafts, upgraded to 300m output shaft, and re shimmed the trans and the same issue persists. When I had it apart, neither the sliders or the dog teeth on the gear looked excessively worn or damaged (see pictures) One thing I'll note is I think I've installed the 3/4 slider on upside down but I'm not sure that would make a big deal or not because 4th is just fine.

-Always ran MT90 fluid only.
-2nd gear usually does it when the trans is colder, when it's warm I don't usually have any issues.
-3rd gear does really consistently though. If I shift slow, it doesn't seem to do it but even any sort of a moderate shift it clunks into gear. At high rpm it definitely seems to grind.
-All other gears are perfectly fine at any rpm.
-Clutch is an ACT 2900 sprung disk (yuck, I know) with an ACT flywheel but this also happened with a OE replacement that was in the car when I bought it.
-Pedal assembly has been welded
-Both Master AND Slave are NEW OEM, not AutoZone or Similar.

Is there a more surefire way to adjust the cables to make sure they are correct other than "put the shift straight up and down and slide the cables on"?
maybe its some sort of clutch disengagement issue still?

Is there other advice anyone can spare to try and get this fixed?

HERE'S a video of me shifting into 3rd pretty casually and you can hear it clunk.

Pictures to show the overall health of the trans while I had it apart.

Any advise is appreciated!

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[Anfurnyy]

get all 4 wheels up and have someone try to turn them while it is in gear and you slowly depress the clutch.

I'll give this a go when I get it back together.

 

[Anfurnyy]

Well dug into the trans last night and found a few concerning things. I guess maybe i just overlooked this before, i don't know. It looks like 3rd gear slider and 3rd gear dog/engagement teeth are pretty cooked.

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I also dont know what happened here but both the sychro springs int he 3/4 hub were broken right after the little hump.. I DID make sure to install them opposite sides when i rebuilt it a couple years ago.

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[twicks69]

Yeah they are trash.

You need to replace the gear and hub/slider. Mario Rajkowski, @fourgsixty3 in here has some good used ones I have inspected and gave back to him yesterday.

 

[Anfurnyy]

Yeah they are trash.

You need to replace the gear and hub/slider. Mario Rajkowski, @fourgsixty3 in here has some good used ones I have inspected and gave back to him yesterday.

I actually have a " HD" setup ready to go in also.

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[Anfurnyy]

Yeah they are trash.

You need to replace the gear and hub/slider. Mario Rajkowski, @fourgsixty3 in here has some good used ones I have inspected and gave back to him yesterday.

I think I may have just figured out what happened.
I think I put the wrong synchro keys in on 3/4 hub..

Bottom is what I just pulled out and top is what came out when I "rebuilt" it.

Would that make a difference?

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[twicks69]

For sure, you need the ones that match the slider being used. Most of the 92.6-99 version sliders use the smaller 663 key with the identification mark on the backside of the key. There were a couple variations that took the larger 777 key, and your 5th/rev hub and slider uses the larger 777 keys on all 1990-1999 ones. The 1990-1992.5 3rd/4th hub and sliders all used the 777 larger keys, and Evo 2/3 style hub and sliders and the remake version sold on Ebay use the 663 smaller keys.

 

[Anfurnyy]

For sure, you need the ones that match the slider being used. Most of the 92.6-99 version sliders use the smaller 663 key with the identification mark on the backside of the key. There were a couple variations that took the larger 777 key, and your 5th/rev hub and slider uses the larger 777 keys on all 1990-1999 ones. The 1990-1992.5 3rd/4th hub and sliders all used the 777 larger keys, and Evo 2/3 style hub and sliders and the remake version sold on Ebay use the 663 smaller keys.

Good to know..I made sure the keys I bought for this 91.5 gearset are the correct ones.
When I ordered from Jack's they listed the incorrect ones for MY slider as 92+ so I just took that at face value.

One other question too, I see that the key is offset inside the slider. Does the 3rd gear side get the larger offset or does the 4th gear side?

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[twicks69]

I'll have to look at some here, been a while. That slider takes the larger 777 keys.

 

[bastarddsm]

That slider is fairly banged up too, but it'll still shift. Some times I think they shift better like that as it does not let the slider by the synchro as easy. Either way cut the tangs off the synchro springs as well. They will allway break off when using a light weight clutch.

The short keys in a slider that needs long keys will bone ya for sure. The key is there to make sure the synchro gets a little torque on it and rotates up to the stop before the slider teeth hit the synchro teeth. If that doesn't happen the slider can get right through and buzz the gear.

 

[Anfurnyy]

They will allway break off when using a light weight clutch.

Is a twin considered light? It seems it should weight more with just how much is in them.

The short keys in a slider that needs long keys will bone ya for sure. The key is there to make sure the synchro gets a little torque on it and rotates up to the stop before the slider teeth hit the synchro teeth. If that doesn't happen the slider can get right through and buzz the gear.

This is exactly what I figured happened. Without the key right size key there, theres nothing to push down on the synchros to engage the gear.

 

[dwb]

Another thing to consider, if you haven't already, is to double up on the 1-2 key springs and then off-set them.

DSM - 4 SPRING 1-2 HUBS - Jacks Transmissions

All of our rebuilds include the installation of an extra set of key springs in the 1-2 synchronizer hubs. This allows the keys to put a little more pressure on the blocker rings for smoother high RPM shifting. The 1-2 blockers are under the most abuse in transmissions over any other gear, so...

www.jackstransmissions.com

 

[Anfurnyy]

Another thing to consider, if you haven't already, is to double up on the 1-2 key springs and then off-set them.

DSM - 4 SPRING 1-2 HUBS - Jacks Transmissions

All of our rebuilds include the installation of an extra set of key springs in the 1-2 synchronizer hubs. This allows the keys to put a little more pressure on the blocker rings for smoother high RPM shifting. The 1-2 blockers are under the most abuse in transmissions over any other gear, so...

www.jackstransmissions.com

I tested this on the 3/4 but the springs didn't allow the synchro to sit down far enough. Are the 1/2 hubs deeper somehow and allow for a 2nd spring?

 

[dwb]

I tested this on the 3/4 but the springs didn't allow the synchro to sit down far enough. Are the 1/2 hubs deeper somehow and allow for a 2nd spring?

I didn't try on 3-4 but 1-2 will definitely allow for two springs. That's what I did and it shifts nice.

 

[Anfurnyy]

I didn't try on 3-4 but 1-2 will definitely allow for two springs. That's what I did and it shifts nice.

I will definitely do that. Anytime I can do try and make not shift better

 

[bastarddsm]

Is a twin considered light? It seems it should weight more with just how much is in them.

This is exactly what I figured happened. Without the key right size key there, theres nothing to push down on the synchros to engage the gear.

IDK put them on the scale vs a stock setup and report back.

Another thing to consider, if you haven't already, is to double up on the 1-2 key springs and then off-set them.

DSM - 4 SPRING 1-2 HUBS - Jacks Transmissions

All of our rebuilds include the installation of an extra set of key springs in the 1-2 synchronizer hubs. This allows the keys to put a little more pressure on the blocker rings for smoother high RPM shifting. The 1-2 blockers are under the most abuse in transmissions over any other gear, so...

www.jackstransmissions.com

Yeah, don't do that. There is not enough room for doubles on 3/4. Also if you are going to dabble with this stuff, make damn sure you know what you are doing. Lots of ways to f*** up. The plus side is you will get fast at dropping the trans.

 

[bastarddsm]

FYI I'm sure this is clear to you, but the springs and keys to almost nothing to apply pressure to the synchro to make it do it's job. That is blocking the slider from moving past untill the gear and hub have synchronized. The ramp angle on the teeth do that. The keys/springs only prep the syncrho to make sure it's ready to block. That is all they do.

 

[Anfurnyy]

IDK put them on the scale vs a stock setup and report back.

Yeah, don't do that. There is not enough room for doubles on 3/4. Also if you are going to dabble with this stuff, make damn sure you know what you are doing. Lots of ways to f*** up. The plus side is you will get fast at dropping the trans.

So don't do the double spring on 1/2?

FYI I'm sure this is clear to you, but the springs and keys to almost nothing to apply pressure to the synchro to make it do it's job. That is blocking the slider from moving past untill the gear and hub have synchronized. The ramp angle on the teeth do that. The keys/springs only prep the syncrho to make sure it's ready to block. That is all they do.

Just so I understand, the keys move with the slider and when shifting the keys are supposed to engage the synchro at least a little bit and START engagement of the gear? And then the tension from the ramp on the keys is actually what really helps put pressure on the synchro and match the gear with the hub while the slider engages the gear?

 

[Anfurnyy]

Yeah they are trash.

You need to replace the gear and hub/slider. Mario Rajkowski, @fourgsixty3 in here has some good used ones I have inspected and gave back to him yesterday.

I did reach out. He has a 95-96 gearset. By the research I've done it LOOKS like that should be a drop in scenario but there's a lot of controversy with the center diff/front diff ring gear. And maybe a few other parts.

Will a 95-96 gearset with input shaft/intermediate shafts drop into a 93+ case, and work with the front/center diff, pinion gear etc?

 

[bastarddsm]

So don't do the double spring on 1/2?


Just so I understand, the keys move with the slider and when shifting the keys are supposed to engage the synchro at least a little bit and START engagement of the gear? And then the tension from the ramp on the keys is actually what really helps put pressure on the synchro and match the gear with the hub while the slider engages the gear?

Yes, I double spring 1/2. Gotta have the right synchros though.

And yes on the process

 

[Anfurnyy]

Yes, I double spring 1/2. Gotta have the right synchros though.

And yes on the process

What are the "right" synchros?
My stuff all tore apart so I'd like to do anything I can within reason to help to help it shift.

 

[twicks69]

You need to use a shallow synchro on 1st to fit double springs on that side of the hub and slider. Please take a side profile photo of your 1st gear synchro so I can confirm which one you have. You can fit 2 springs on the 2nd gear side with a double synchro no problem. You cannot fit double springs on the 3/4 and 5/R.

 

[Anfurnyy]

You need to use a shallow synchro on 1st to fit double springs on that side of the hub and slider. Please take a side profile photo of your 1st gear synchro so I can confirm which one you have. You can fit 2 springs on the 2nd gear side with a double synchro no problem. You cannot fit double springs on the 3/4 and 5/R.

I will do that tomorrow.

Any answers in if the 95-96 gearsets will work with the 93+ stuff?
I've read pretty much every post on it I could find including your post about putting 1g internals in a 2g case but couldn't really come to a conclusion.

 

[twicks69]

Yeah it all works together. 1992.6-1999 gearsets all share the same tooth profiles, synchros and hub/sliders. Dog tooth profile changed a couple of times from slanted or tripod, material changes for hub and sliders, roll pin orientation of 5th/rev shift fork and shift rail, among a few other changes but they generally work together. I can answer more specific questions quicker than blanket statements because it would take me some time to type out all of the variations from memory.

Reverse idler gear and rail for example do not interchange because of the transmission case variation. The rail length and the gear backside height are different between 1g and 2g.

1989-1991.6 5th gearset, main case oil guide and 5th shift fork/hub and slider and 5th gear cover for example need to stay as a matched set if you are swapping into different year stuff because of the oil guide orientation and shape. It can be all swapped into 1991.6-1996 as a matched set of components, but to use in a 97-99 case you would have to change out the 5th/reverse shift rail for a 1991.6-1996 style one due to roll pin orientation.

1989-1991.5 and 1991.6-1992.5 gearsets will work in a 1992.6-1999 transmission case but you need to change the 3rd/4th shift rail to a 1991.6-1992.5 or Evo 2/3 3rd/4th shift rail due to the 4 degree roll pin orientation difference between 2 hole and 3 hole style shift forks.

So as you see, there are variations, but you just need to know which parts work with, and which parts do not, to get it all to match up.

 

[Anfurnyy]

Yeah it all works together. 1992.6-1999 gearsets all share the same tooth profiles, synchros and hub/sliders. Dog tooth profile changed a couple of times from slanted or tripod, material changes for hub and sliders, roll pin orientation of 5th/rev shift fork and shift rail, among a few other changes but they generally work together. I can answer more specific questions quicker than blanket statements because it would take me some time to type out all of the variations from memory.

Reverse idler gear and rail for example do not interchange because of the transmission case variation. The rail length and the gear backside height are different between 1g and 2g.

1989-1991.6 5th gearset, main case oil guide and 5th shift fork/hub and slider and 5th gear cover for example need to stay as a matched set if you are swapping into different year stuff because of the oil guide orientation and shape. It can be all swapped into 1991.6-1996 as a matched set of components, but to use in a 97-99 case you would have to change out the 5th/reverse shift rail for a 1991.6-1996 style one due to roll pin orientation.

1989-1991.5 and 1991.6-1992.5 gearsets will work in a 1992.6-1999 transmission case but you need to change the 3rd/4th shift rail to a 1991.6-1992.5 or Evo 2/3 3rd/4th shift rail due to the 4 degree roll pin orientation difference between 2 hole and 3 hole style shift forks.

So as you see, there are variations, but you just need to know which parts work with, and which parts do not, to get it all to match up.

Basically what I'm wanting to do or use is Mario's entire input and intermediate shafts including all gears on it. With the possible exception of the "HD" 3rd and 4th gear setup w/ shift rail hub and slider.. outside of that everything else will be 93+

Here's a couple pictures of the side profile of 1st gear synchro.

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[twicks69]

That is a shallow 1st synchro, you can run 2x springs on that side of the hub as well then.