Advertisement

MT-82 is my 4 gear going out?

Pbenz

Member
Joined
Sep 10, 2019
Posts
17
Reaction score
0
Location
Bay area
First Name
Benz
Vehicle(s)
2017 mustang gt
My 2017 Mustang gt Roush phase 1
So I just installed a bigger TB, 82mm pulley, injectors, bap & and a tune, I was racing my friend with an roush rs3 and my 4 gear went out.. I think.. not really?

So before this the stock rev is 7k.. after my tune I’m Reving to 7400-7600rpm I noticed my shifts from 3rd to 4th going from 7600rpm is grinding and feeling a little shitty at some shifts but it got better. Then when I was racing tonight my 4 gear just went out kinda. I revved my 3rd gear out then went for the change and it was like I totally lost 4gear it was 1/4 of the way in but just free revved then I put it in neutral and back into 4th and it was fine... I go to rerun it and the 3rd to 4th shift is going in but horrible feels sloppy weak like it’s so soft and only going in half way but it works perfectly fine holds the gear and power until I shift next.
I also drive normally and it feels normal no more soft shitty shifts but when I get back on it going from 3rd to 4th it feels so weak and doesn’t go in all the way??? What happened is my 4th about to go or what? Also what’s the best way to go about this if I need a new trans? Rebuild kit, how much is labor?
Or go with a stage one cailmer mt-82? How much would be the install for that?? I’m looking for a cheap budget friend way to fix this thanks!

Also my car is a 17 with the roush from factory. I’m 18k miles in do you think if I reflash it back to stock I could take it in for warranty work? Can i leave my TB pulley and injectors in or what?
 

NoVaGT

Well-Known Member
Joined
Sep 29, 2016
Posts
4,216
Reaction score
2,717
Location
Northern Virginia
Vehicle(s)
2019 PP1 GT Kona
About tree-fiddy.
 

tokuzumi

Well-Known Member
Joined
Apr 3, 2019
Posts
363
Reaction score
170
Location
Atlanta
Vehicle(s)
2004 Escalade ESV
I'd take it back as close to roush stock as possible before trying to claim any warranty work. Probably a syncro issue.
 

I Bleed Ford Blue

Well-Known Member
Joined
Nov 24, 2018
Posts
666
Reaction score
349
Location
North East OHIO
First Name
Mike
Vehicle(s)
2017 grabber blue GT PP1 convertible, 2018 blue metallic explorer sport
So under normal driving it shifts fine but under heavy throttle it doesn't? Sounds like you need a shifter support bracket and/or a new shifter. If you prolong it much more you may need a new transmission too.

A little background, back in 2005 when ford introduced the S-197 they mounted the shifter body to the underside of the trans tunnel to reduce NVH. They then used a link rod to connect to the trans and actually shift the trans, when the engine rocks or torques to the side under heavy throttle the trans moves with it, causing the link rod misalignment and binding, causing hard shifting and eventually broken parts inside the transmission. From 2005 to 2010 it was not a big issue, but fast forward to 2011 when ford introduced the 400+ hp coyote and the MT-82 and now it has become a lot more common. In 2015 they redesigned the whole shifter mount and reduced the misalignment under heavy load, but it was still there. When you add forced induction into the equation it gets even worse. There are only two fixes that I know of, swap out the weak and poor designed MT-82 for a different trans like the T-56 magnum or the tremec used in the GT350, or install a shifter support bracket. The bracket is the cheaper of the two options. The bracket bolts to the back of the trans and supports the shifter so you can unbolt it from the body of the car and bolt it to the bracket so now when the trans rocks to the side under heavy load the shifter moves with it, thus eliminating the misalignment making the issue a non-starter. But be warned, the bracket will not fix a broken or damaged trans, it only eliminates the root cause. If your trans is damaged or broken you will need to get that taken care of also. If you still have warranty use it and get the trans fixed first and then add the bracket after you get the car back. If your out of warranty and have to pay for a new trans out of pocket, you might want to consider a swap to the T-56 magnum XL it costs about the same as having the dealer install a new MT-82 but it is rated for 700+ hp and has the shifter mounted to the trans housing itself so no more misalignment. Blowfish racing makes a bracket that works with the stock shifter and runs about 3 bills, barton shifters makes one too that works with their own shifter, since you have to buy a new shifter also you could be around 1K for the barton route. Both brands also have an approved driveshaft safety loop integrated into the backet
 

Cobra Jet

Well-Known Member
Joined
Feb 12, 2015
Posts
6,141
Reaction score
3,030
Location
NJ
Vehicle(s)
2018 EB Prem. w/PP and 94 Mustang Cobra
It’s possible that the 3-4 shift fork is damaged.

There are a few TSB’s that apply to the 2018 MT82 and multiple shift fork failures.

It is quite possible that even in a 2017, the 3-4 shift fork has failed if you were exerting force while shifting or when shifted at a higher than normal RPM range.
 

nastang87xx

Well-Known Member
Joined
Jun 5, 2015
Posts
6,432
Reaction score
3,989
Location
Wisconsin
Vehicle(s)
2016 GT350 Track Pack
It’s possible that the 3-4 shift fork is damaged.

There are a few TSB’s that apply to the 2018 MT82 and multiple shift fork failures.
If the fork was gone it wouldn't even hit 4th and you would be able to freely move the shifter into the 4th position without engaging the clutch. Not fork related. That's a 2018 issue very exclusively.
 

kz

Well-Known Member
Joined
Oct 26, 2014
Posts
2,380
Reaction score
864
Location
West Chester, OH
Vehicle(s)
Mustangs & F150
It’s possible that the 3-4 shift fork is damaged.

There are a few TSB’s that apply to the 2018 MT82 and multiple shift fork failures.

It is quite possible that even in a 2017, the 3-4 shift fork has failed if you were exerting force while shifting or when shifted at a higher than normal RPM range.
It's not fork - 15-17 had relatively weak 4th gear - which is likely what this is.
 

Advertisement


Cobra Jet

Well-Known Member
Joined
Feb 12, 2015
Posts
6,141
Reaction score
3,030
Location
NJ
Vehicle(s)
2018 EB Prem. w/PP and 94 Mustang Cobra
If the fork was gone it wouldn't even hit 4th and you would be able to freely move the shifter into the 4th position without engaging the clutch. Not fork related. That's a 2018 issue very exclusively.

Yes those referenced TSB’s are exclusive to the 2018’s w/ MT82, however that’s not to say that a pre-2018 could have a shift fork failure.

Also I’ve had prior Mustangs with manual transmissions and if the shift fork has been bent, it will still allow the shifter to go into selected gear, but in doing so it’s going to feel different where it may be notchy or not want to go into the gear as smooth as it did before being damaged.

There may be other things that it could be - chipped gear cluster, damaged synchro, bad shifter design, shitty hydraulic clutch line, etc.

The OP should examine the shifter mounting and check for any damages or premature wear. Then check the hydraulic line for any seepage or it being loose (another thread covers that whole subject matter).... start with the easiest and cheapest process of elimination.
 

2017GBGTPP

Well-Known Member
Joined
Jul 2, 2016
Posts
513
Reaction score
587
Location
Tempe, Arizona
First Name
Dan
Vehicle(s)
2017 Grabber Blue Premium Mustang GTPP with Recaros
Blowfish racing makes a bracket that works with the stock shifter and runs about 3 bills, barton shifters makes one too that works with their own shifter, since you have to buy a new shifter also you could be around 1K for the barton route. Both brands also have an approved driveshaft safety loop integrated into the backet
Full Tilt Boogie Racing also has a bracket for like $70. It doesn't have the driveshaft loop, but does the same thing otherwise.
 

I Bleed Ford Blue

Well-Known Member
Joined
Nov 24, 2018
Posts
666
Reaction score
349
Location
North East OHIO
First Name
Mike
Vehicle(s)
2017 grabber blue GT PP1 convertible, 2018 blue metallic explorer sport
Full Tilt Boogie Racing also has a bracket for like $70. It doesn't have the driveshaft loop, but does the same thing otherwise.
Good to know, thank you.
 

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Posts
1,128
Reaction score
270
Location
Nashville
Vehicle(s)
2016 GT
That was very difficult to read. But it sounds like it could just be an issue with the factory clutch not wanting to fully disengage about 7k.
 

Pbenz

Member
Joined
Sep 10, 2019
Posts
17
Reaction score
0
Location
Bay area
First Name
Benz
Vehicle(s)
2017 mustang gt
Do you guys think I just need a new clutch? Or a whole tranny?
 

Advertisement




Advertisement




 
46 - Roush Performance - 1
Advertisement
Top