Sending The Miata To 100MPH On Jackstands: The Gremlin Chase Part 4

[admin]

I’m pretty excited to get the ZF transmission into the car, just gotta keep pushing forward and get this thing figured out! I know it’s going to be great when it’s all …

[BigBen]

Really hoping you can sort this out, doesnt this damage the chassis in the long run? I guess next thing is BMW style driveshaft like you said couple vids ago?

[Homebuilt Racing]

Have you tried changing gearbox bushings/mounts for something with different stiffness? since vibrations are speed related, there should be something with that speed or frequency that causes it. And resonanting frequencies are determined by stiffness of elastic elements and damping. So I'd tried to replace all bushings with solid mounts at least temporary for testing.
and if it will not help – have a look on structural rigidity of places where components are mounted. Maybe those are acting as springs in your case…

[NippyMoto]

Damn Greg you are persistent with trying to make a car go fast that just doesn't want to go fast haha

[MiG Ren E’]

safety mode to keep your from going over 75 mph .. this must be so anoying something is out of sync for sure

[Eric Hengesbach]

Hey Greg I don’t know if this could be it or not since you were saying there are others running this kit as well with no issue but when you look at how the trans bushings are setup technically since the bolt passing through is still sits both on the transmission and on the mount that is bolted to the body it still could be sending vibrations through it even with that bushing in the middle. Think about like the diff bushings and the motor mounts. The bushing completely isolates one part of the car where no metal is touching besides either the body or what is being mounted. Maybe try throwing some rubber on one side of those bolts to see if that might at least help a little bit

[Zesty]

I cant remember, did you already change the diff out before?

[carrington cape]

Greg, it may be worth trying the jack stand test again with the driveshaft removed. I’m not entirely familiar with the trans you are running. But if it’s possible to put it in gear and bring the engine/trans speed up with the driveshaft removed then you’ll know for sure that it’s coming from the trans. If you don’t get anything then you know it’s driveshaft or rear end related. I’m sorry if you’ve already cover this I just thought about it while watching. Hoping for the best for you

[Andrew Hobbs]

Would like to have seen a camera angle showing the rear of the transmission during vibration

[Andreas Lindkvist]

In Sweden we have a saying "Trägen vinner".. which is from the north where people barely speaks (hence the shortness).. means "Stubborness wins".. just keep at it, it will show itself eventually!

[Will van Houten]

Creigh ze engineer

[Martin Armstrong]

Hey just thinking, how stiff are the differential mounts???

[acornhead50]

Expectation: watching the video prepared to point out the problem for Cregg

Reality: what the shit

[Miguel Gf Miata Bolivia]

Is the worst feeling when you doesnt find de problem! I wish you the best lucky possible!! You are each time near! Cheers man

[Alex Chulzhanov]

Well I’m glad I changed from a 260 to a ZF 6-speed before this happened lol.. Good luck Greg, maybe the custom center support driveshaft can solve your issue.

[ThePAINtrain 10]

I would say it's your diff. If you over tighten the center nut on the input on the diff it can cuase diff binding. Mabye resulting in shake. Thats on my truck. Miatas might not be built the same way. I am no car expert. Just trying to give ideas. I really hope you track this problem down. I have just started my own miata adventure. You are possibly the most valuable resource in the miata car scene. Turbo coming soon.

[Jack Mcdonald]

Could have just used a clear drink bottle instead of container. For next time😉

[IKilledJack]

Try swapping those rubber transmission mount bushing for something hard, and see how that makes a difference. Like back on the jack stands and driving. The symptoms i would be predicting is slightly more vibration at low speed, and reduced vibration at high speed

[Colman Au]

May or may not be an issue, the diff looks like its mounted from the PPF to the chassis with no bushings, I know your setup has delrin diff bushings but if the diff is still mounted solidly to the chassis in other places, it may cause vibration?… it's weird because driveline vibes are usually at low speeds

[CoTY Rusher]

@7:35 did anyone else catch the two missing bolts out of the k miata nose mount or am I crazy???

Edit: Just realized fifteen other ppl pointed this out sorry Greg for the repetition lol

[Casual Tryhard]

Have you tried swapping the diff?

[S. Byrd]

Have you checked the pinion angle of the tranny and diff?
Also is it with the clutch engage or disengage make a difference?
And check your diff. Carrier and pinion beatings for play.

[Author]

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