Transimissions: Your expertise is needed. Yes, you.

[Guest bocce15]

About 2 months before I garaged my Z for the Winter, when I would shift into 2nd gear from either 1st or 3rd it would be difficult and grind unless I eased it in real slow. Many people have told me that I would have to get the synchronizers replaced, get the transmission rebuilt, or get a new/used transmission. These are all very expensive options.

 

I have been doing some research online and some people have claimed that they have had this problem with different cars and have fixed it by simply changing their transmission fluid to Redline MT90. Has anyone ever heard that this would work? I am going to try it, or course. Especially since the guy before me could have put some really shitty transmission fluid in there. If he took it somewhere like a Jiffy Lube or something - do they carry good transmission fluid at those places to put in performance cars?

 

Lets say that this doesn't work and I have to go with a new or used transmission. Where is a good place to get this done? I want a place that puts a guarantee on their work in case it fails again in the near future. I don't care that it is expensive because it is going to be expensive no matter what.

 

I really think that this Redline MT90 idea will work, because the car only has 40,000 miles on it and a new transmission just sounds like overkill.

 

Does this problem have to be the synchronizers? Is there anyting else I can try if the Redline transmission fluid idea fails?

 

THANKS FOR ANY HELP

[controler]

I think the MT90 is only GL4 based. This might be good for older transmissions, but most newer transmissions require GL5. Regular Redline 75w90 is GL5, and remember to get NS for non-limited slip. I put it in my MkIII supra tranny, and yeah it helped but 2nd gear syncro was almost gone anyway. Ultimately this is just a temporary fix, you will have to get a new transmission or have your current one rebuilt. You could get a used tranny from a japanese importer, but you might have to deal with different gear ratios. That would be your cheapest route, unless you could find one in good shape at a junk yard. I was lucky and bought a car with a blown motor, but the tranny was good and I parted out the rest of the car smile.gif

[SupraGlue]

How badly did he abuse the tranny? I bought a used Camaro years ago with 16,000 miles where the second gear synchro was already dying, most likely due to the incompetence of the previous owner.

 

You may as well try a fluid change, but it sounds like a bad synchro on second gear to me. You should be able to find Redline or Royal Purple at a performance store like Jeg's (that's where I get mine)

[Moe7]

sounds like u have the same synchro problems us 240 people have. after doing plenty of research i decided to try Redline lightweight shockproof and i have nothing but good things to say about it. it made nearly all my my synchro problems unnoticable and i no longer have the terrible grinding trying to get into second gear, even from a cold start. plus its a thicker formula so it gives a better feel going into gear. i know countless other 240 people who have the same results from using Redline and i have yet to see a downpoint, can't hurt to try... MT90 and heavy shockproof are also very good options smile.gif

 

p.s. - my tranny has 103k miles on it...

[SupraGlue]

Be careful to get the Shockproof Heavy warmed up in cold weather. Some people use that in the diffs in Supras, and it takes a while to warm up when it's cold out. The diffs (worm gear Torsens) are locked up like a spool until the fluid gets a little heat in it.

 

For Spring-Summer driving, it should be fine, though. I've heard nothing but good things from the people using it.

[Renner]

1st, check your clutch adjustment. Make sure that the clutch is getting totally disengaged when you push the pedal all the way down, because if it is not, it will make the car harder to shift, and will actually cause your synchros to wear out faster, since they are having to work against more loads to speed up or slow down the next gear.

 

Redline will definitely help your problem. I have put it in both of my TTZ's and it has made a noticeable improvement, as it has for many other Z’s according to tt.net. The 4th gear synchro is actually the weak point in the tranny, it normally wears before any other, just from normal use, but not usually until much higher mileages if the car wasn’t totally abused. You will usually notice a grind when downshifting from 5th to 4th if you have the worn 4th gear synchro prob, but most make it to 100K miles before having any probs. If you are not having any 4th gear probs, but you are having grinding in 2nd and 3rd, and it’s not from the clutch or crappy/low fluid, then your tranny was almost definitely abused.

 

The 94+ trannies had some upgraded internal parts, and the J-spec models got another upgrade in 97 with some Nismo parts. So if you were going to try and find a used one, you would be downgrading to go any earlier then 94. Downgrading in terms of synchro strength, which is just related to synchro lifetime. The overall power handling strength of all of the transmissions is very good, and is pretty much the same throughout the years.

 

If it were me, I would honestly have it rebuilt if you feel you have to do something, since you already have one of the better trannies in terms of stronger internals, and who knows what the condition would be of a used one that you bought. Just make sure that a reputable shop does the work, because getting the parts correct can be a bit of a bear. I can't think of anybody locally off the top of my head, but Z1 Motorsports in Georgia does a bunch of Z32 work, so they could prob help you out as long as you could ship it to them.

 

I have rebuilt a few trannies, including the one in my old TTZ (91), and getting the correct parts for it is actually quite tricky compared to most other rebuilds. Since some of the parts were updated, the factory part numbers will reference a “service file” when you talk to a dealer parts guy, or basically reference to another part number for a newer/different part. Only problem is that not ALL of the parts will service file, and not all of the parts will match up, and there isn't a good system to figure out exactly which parts do match up. So you can get one part, such as an operating sleeve, which did get updated, and another part, such as the gear itself, that is not updated, or which may not work with your current input shaft if it is updated, and they could all be listed as the correct parts for a 96 TT. The mismatched updated/non-updated parts will cause huge shifting problems if not done correctly, since the engagement teeth will not be the same. Some of them use the traditional pentagon shaped teeth, where others used wedge shaped teeth.

 

So I guess the moral of the story is, if you can, send it to a shop that has done a few Z trannies before, since they will already know what to do with yours in terms of getting the correct parts. You may have less issues with it then I did, since yours is newer, but I am sure that you will run into a few of the “service files”, so I figured I would give you a heads up, because not just any old tranny shop can do the rebuild correctly.

 

BTW, if you would like me to take a quick test drive sometime when the weather gets nice, just to check it out and get a second opinion to see if it’s something severe or not, let me know, and I can help you out, since I am pretty familiar with the Z’s.

[Guest bocce15]

Thanks everyone for your advice. This definitely helps out.

 

I'll let you know when I am taking my car out of the garage Renner so you can have a test drive. It will most likely be in early April.