Manual Trans. Thud when shifting

[DeepImpactBlue2015EB]

my friends 370z has a massive thud sound, my 2008 Civic Si had the same thud for the 8 years I owned it. My Ecoboost also has it, I think everyone here needs to relax. Theres nothing wrong with our transmissions.

Sponsored

 

[DeepImpactBlue2015EB]

Ive been driving manual since 2002 and I've owned and driven several manual cars and that clunky/thud sound is in almost every car Ive driven, some worse than others. Most of the time they are from dead stops going into first or reverse.

 

[dgc333]

I have been driving manuals continiously for 40 years and have never had a thud during shifting and my EB with PP doesn't do it either. It may be common with the Mustang and may not be harmful but it certainly isn't normal.

 

[Hogie]

My old 240z had a similar thud while shifting, but it was because the 40 year old strap holding the differential down was worthless and allowed the diff to move around a bunch.

I don't think the fix for this will be as easy as adding in a bumpstop.

 

[Varekai]

my friends 370z has a massive thud sound, my 2008 Civic Si had the same thud for the 8 years I owned it. My Ecoboost also has it, I think everyone here needs to relax. Theres nothing wrong with our transmissions.

This +1

 

[EchoTango]

I don't doubt this is anymore than annoying. Ford Service thinks it worth following. Ford engineers would have surely by now provided a fix if it thought the problem would be costly to Ford. Here's a thought. Say someday you decide to sell your Ford masterpiece. You take the prospective buyer out for test drive and right off he(she) notices the clunk. You tell him(her) that that's normal. All Mustang sticks do it. Prospective buyer thinks, "This is a real muscle car. This guy(girl) has probably beat the hell out of it like it was a rental." Just a thought.

 

[foghat]

I don't doubt this is anymore than annoying. Ford Service thinks it worth following. Ford engineers would have surely by now provided a fix if it thought the problem would be costly to Ford. Here's a thought. Say someday you decide to sell your Ford masterpiece. You take the prospective buyer out for test drive and right off he(she) notices the clunk. You tell him(her) that that's normal. All Mustang sticks do it. Prospective buyer thinks, "This is a real muscle car. This guy(girl) has probably beat the hell out of it like it was a rental." Just a thought.

Just send him the link to this thread if you think he won't believe you.

 

[Genxer]

I am curious to hear impressions from Mustang owners in Europe, for contrast.

Personally, I have only experienced shifting transaxles with any frequency. On those I've driven the neutral to first or neutral to reverse is often notchy and requires a gradual push to allow engagement. A feel thing. Also 2-1 shifts have to be done almost at a stop or they are going to grind. I can't wait to test drive the MT82 for comparison. Different designs of course but both use sychros. Reverse I get because of straight cut gears in the transaxle. Not sure about 1st.

 

[FordService]

2000 miles on PP GT. Have same thud when putting in gear and shifting in bottom gears, babying or aggressive shifting. Ford needs a fix and needs to first acknowledged there is a problem. I've never missed a shift. This is poor engineering and Ford knows it. I've owned a few new Roadsters, and they did not have this problem. I'd take it to dealer, but sounds like this is not a dealer fix--at least not yet.

I'm here to assist, if you want to have it checked out. Just shoot me a PM. I'll gather some info and get this escalated.

Jeff

 

[MJS-P51]

I just saw this on CJPonyparts.......http://www.cjponyparts.com/blowfish-racing-manual-shifter-support-bracket-2015/p/MSSB1/

Not sure if it has been mentioned yet in this thread but was wondering if anyone has tried this bracket yet. Bill seems to think it improves the shifting quite a bit. I'm definitely curious if this addresses some of the issues many of us PP owners are facing....

 

[aeropaul]

I haven't been monitoring this thread very much lately, but I feel compelled to chime in after being used as a source (thanks BTW, I'm glad my mechanical follies can benefit the community).

The thud has nothing to do with the shift linkage. By design, the shift linkage cannot feed back any impulses into the body to cause a resonance (thud). Nor is there enough mass moving in the longitudinal direction to generate such a resonance. At one time, I had thought that the shifter mount was responsible for transmitting the thud, due to its rigid connection to the transmission. But the bushing mount at the body would prevent any NVH transmission here.

I'm hesitant to say this aloud for fear of getting bombarded, but I don't think the MGW solid shift linkage is the proper theoretical answer. The joints in the shift linkage exist for a reason, and it is to allow the transmission to move relative to the body and not impart radial loads on the shift shaft bearing. Practically speaking, the loads are low enough that no problem occurs. The Barton shifter reuses the stock shift linkage (while replacing the shifter housing and mount) for this exact reason. The MGW shifter coupled with the blowfish bracket would totally negate the issue of differential movement, effectively turning the shifter into a trans-mounted design. (For historical reference sake, the S197 shift problems were caused by the weak tie-rod between the trans case and body mounted shifter). As an aside, I think the MGW shifter unit itself and its mount to the body and trans housing is a beautiful product. So is the Barton, for that matter.

And, of course the MGW won't fix the issue, because the shifter is not responsible for the problem in the first place.

The only thing with enough inertia to cause a resonance like this is the transmission internals. The occurrence of the noise during a N-1 shift at a stand still indicates wind-down due to synchro friction/contact. As my referenced post stated, the mounts and body structure have a LOT to do with what NVH is passed to the occupants.

Last point: This isn't the first time I've heard the Tremec 3160 that will be in the GT350 pushed as the panacea. And I know everyone loves to throw around rating numbers like they understand them. The MT82 is rated at 500 N-m of torque for a Max GVW of 4250 kg. That's 370 ft-lbs of torque @ 9400 lbs MGVW. The first number is the one thrown around a lot, the second number is the one conveniently ignored. The Tremec 3160 is rated at 550 N-m @ 3000 kg MGVW, which translates to 450 ft-lbs @ 6614 lbs. This is a sustained rating. Both transmissions are or will be used in a sub 3700 lb car. Torque rating will increase as MGVW decreases (not linearly though, since gear stress equations are not linear relationships). They're similarly rated transmissions, neither are being used outside of their rating spectrum.

Not to say that there aren't any issues with the MT82, I read through the 3rd gear bump and grind thread. Thankfully I don't have that issue. But I've also read a few threads about the auto having issues too. Neither is terribly surprising given the volume at which these cars are made/sold.

 

[dwaleke]

The MGW shifter coupled with the blowfish bracket would totally negate the issue of differential movement, effectively turning the shifter into a trans-mounted design. (For historical reference sake, the S197 shift problems were caused by the weak tie-rod between the trans case and body mounted shifter). As an aside, I think the MGW shifter unit itself and its mount to the body and trans housing is a beautiful product. So is the Barton, for that matter.

The current design of the MGW shifter mounts it completely to the transmission and no connection points to the body. No need for the blowfish bracket to accomplish this.

 

[evin23]

EXPERIENCED THE SAME, HAVE MANUAL BUT SHIFTING INTO SECOND REQUIRES A BIT MORE FORCE THAN OTHER GEARS, IVE NOTICED THIS CHANGED WHEN I ACCIDENTLY TRIED SHIFTING INTO FIRST GEAR GOING AT 15 MILES PER HOUR.

 

[aeropaul]

The current design of the MGW shifter mounts it completely to the transmission and no connection points to the body. No need for the blowfish bracket to accomplish this.

Oh snap! When MGW was first posting about the 2015 shifter, it looked a lot like the S197 MGW shifter, with a slider rear mount to the body. I did not pay attention to the eventual release of the 2015 shifter, so after I read your comment I looked at the production shifter. I really like the new bracket. That will be my next modification. Maybe one-piece driveshaft at the same time. Beautiful.

 

[steviebee72]

GT PP, have the thud..

Out of curiosity anyone swap out the drive shaft to one of the 1 piece units and still have the thud ? my Axles shafts are tight, they don't move around or feel loose.
also why is the drivers side shaft thicker than the passenger side ??

but the drive shaft moves around quite a bit in that center uni bearing thingy ? I could easily move that drive shaft about an inch and clunk it around?

What else do you do when your bored, lie under your car and try to figure out what the famous thud is!!!


2015 DIB 50 year GT PP

Sponsored