• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

tremec t5 resonance in 4th and 5th gear

culberro said:
I've also got a billet t5 yoke here and some m47 guibo parts that I've been tasked with making into one part. Maybe that will be enough damping to help the rattle/oscillations in the t5.
Click to expand...

Very interested to see what you do with this. I am in the process of getting a machine from Mori to produce this very product.

I think having something like this would go a long way to help these cars deal with the slop of the transmissions.
 
Any chance we could have this in a year? This would be very exciting. On the subject of NVH, besides the horrible resonance from my driveshaft, the most annoying and loudest thing about this transmission in my opinion is not the decel gear rattle, but the idle gear rattle with the clutch out in neutral. Maybe mine is worse because I have a vacuum leak and my car idles poorly. Also, I actually really like the subtle gear whine this transmission makes.
 
sloopy said:
Any chance we could have this in a year? This would be very exciting. On the subject of NVH, besides the horrible resonance from my driveshaft, the most annoying and loudest thing about this transmission in my opinion is not the decel gear rattle, but the idle gear rattle with the clutch out in neutral. Maybe mine is worse because I have a vacuum leak and my car idles poorly. Also, I actually really like the subtle gear whine this transmission makes.
Click to expand...

I think it will happen this year, waiting to hear back with quotes and financing terms.

I had a similar problem with my TKO, after I added a clutch fork return spring, it went away.
 
Awesome :^) I have a clutch fork return spring. I guess I should address the vacuum leak and see how bad the rattle is after that.
 
blkaplan said:
Very interested to see what you do with this. I am in the process of getting a machine from Mori to produce this very product.

I think having something like this would go a long way to help these cars deal with the slop of the transmissions.
Click to expand...
I've worked with a lot of gear shops in the last few years, and doing something like this in-house is going to cost more than farming it out in my experience. Somehow domestic gear manufacturing is actually affordable.
There are a few shops that can do the splines for ~$35 per part with a quantity of only 20.

@blkaplan I talked with Jody at 5speeds.com about this, and he doesn't think the guibo is going to solve the issue, as he's put t5s in a lot of 4cyl cars without issues. He thought the main cause of vibrations were: Engine and trans mounts needing a change to deal with the different harmonics of the t5, and changing u-joint angles under power and decel (motor mounts, axle bushings). The guibo might help mask these issues, but it's not solving the problem.
I tend to agree with him. The 240 rally cars I've set up with t5s are full sphericals in the links and axle (front trailing arms are still rubber) and they don't have this issue as long as it's a balanced 2pc design and the pinion angles are adjusted accordingly.
 
Last edited:
culberro said:
I've worked with a lot of gear shops in the last few years, and doing something like this in-house is going to cost more than farming it out in my experience. Somehow domestic gear manufacturing is actually affordable.
There are a few shops that can do the splines for ~$35 per part with a quantity of only 20.

@blkaplan I talked with Jody at 5speeds.com about this, and he doesn't think the guibo is going to solve the issue, as he's put t5s in a lot of 4cyl cars without issues. He thought the main cause of vibrations were: Engine and trans mounts needing a change to deal with the different harmonics of the t5, and changing u-joint angles under power and decel (motor mounts, axle bushings). The guibo might help mask these issues, but it's not solving the problem.
I tend to agree with him. The 240 rally cars I've set up with t5s are full sphericals in the links and axle (front trailing arms are still rubber) and they don't have this issue as long as it's a balanced 2pc design and the pinion angles are adjusted accordingly.
Click to expand...

It's not the only product I will be getting it for, but it is one of the things I had in mind, either a Guibo adapter or something else that can improve that interface.

I do agree that there are huge benefits to be gained by improving the engine and trans mounting of these engines.

With the right tooling, the splines are easy enough to cut, I think the main thing is getting the fit dialed in how you want it.

There are always a way to do it cheaper, I'm looking for ways to do it better.
 
Seriously, I am very excited about this and will order it as soon as it's available. I'd be down to buy and test a prototype as well. Will this involve something like drilling and tapping a threaded hole down the center of the output shaft and bolting this adapter on?
 
sloopy said:
Seriously, I am very excited about this and will order it as soon as it's available. I'd be down to buy and test a prototype as well. Will this involve something like drilling and tapping a threaded hole down the center of the output shaft and bolting this adapter on?
Click to expand...

I will explore that for sure, Having an extra unlocked slip yoke is something that should be avoided when trying to improve this kind of stuff.
 
I just dropped off my axle to get it balanced and checked out for any other issues. Now I'm going to play with the crossmember adjustments to get the transmission output pointed right through the center of the center support. Any suggestions on how I can do this? Some sort of laser that can sit on the end of the output shaft and attach a piece of paper to the back side of the center support?

I have factory torque rods so I can't adjust my pinion angles for now. And I have lesjofors sport springs in the rear which are pretty low. Unfortunately, Ben's hybrid adjustable torque rods have been out of stock for some time now and I don't want the poly adjustable torque rods offered by the other guys.

@blkaplan Any word on the t5 giubo project? I'm very excited about it.
 
Got the driveshaft back. The guy said the modified front section was out of line and the balance was way off, but he thinks everything should be good now. So I'm hoping this puts this issue to rest. I'm still going to try to make sure I have the transmission output aimed at the center support as best as I can before I put it back together.
 
sbabbs said:
Yeah it's called a BMW getrag 265 or a volvo M90 transmission. Why put noisy vibrating less power handling junk instead in?
Click to expand...
Those transmissions have lame gear ratios. My T5z has awesome ratios, handles all the power I'll be able to give it, and it is very cool might I say.
 
OP, I had very similar groaning/humming through the body of my old 242 when I put a T5 in place of the broken M46. The semi-fix for me was the engine and transmission mounts. I had RSI engine mounts with a energy transmission mount. I swapped the trans mount for the cheap anchor rubber one and 90% of the new T5 noises were gone. This was with the original 2-pc driveshaft (fully serviced, balanced, and with the T5 slip yoke added), new DS center support, IPD adjustable torque rods. Never had vibrations, but definitely had a hum to it. What trans mount are you running?
 
You must log in or register to reply here.
Back
Top