DIY Clutch/Synchro replacement on 91-96?

[Markbert]

Hi All,

I've got a 94 NSX, a mechanical engineering degree, some time this winter and very little practical experience other than basic automotive maintenance (changing fluids/filters and the like). I do, however, actually enjoy working on the car and was thinking of replacing the clutch and synchros in my 94 more as a precautionary measure than out of real immediate need (the car has 40k miles and has always been babied).

I've searched the FAQ and read the Service Manual, but would like a reality check from the good folks here before going any further and jumping off the deep end with part purchases:

1. How can I best guage the life remaining in my synchros and clutch?

2. Has anyone attempted this on their own in a home garage? (i.e. no specialized or terribly expensive equipment) What were your experiences?

3. How difficult is the install on an OEM twin disc clutch versus an aftermarket single disc unit such as the Comptech Powergrip II?

Thanks all for the help.

Mark

 

[DanO]

Sounds like a cool winter project! The immediate problem I see is physical one. How are you going to remove the tranny? I’m not sure how much clearance you need to safely get the tranny out. Maybe jack stands are enough, maybe not, maybe someone here knows!

Sounds fun!

DanO

 

[nsxtasy]

Just remember, some folks get 90-100K miles on their clutches, so it may not be due in the immediate future...

Originally posted by Markbert:
1. How can I best guage the life remaining in my synchros and clutch?

I'm no mechanic, but I think you can check the thickness of the friction material in the clutch. And I think you have to go to a lot of work to open up the tranny to do this. Is that right, guys?

 

[sjs]

Originally posted by nsxtasy:
Just remember, some folks get 90-100K miles on their clutches, so it may not be due in the immediate future...

I'm no mechanic, but I think you can check the thickness of the friction material in the clutch. And I think you have to go to a lot of work to open up the tranny to do this. Is that right, guys?

Right on both counts. At 40k and "babied" you could well have 50% or more left on the clutch. I've got about double that including a lot of them with turbos. Or, the person who babied it may not have known correct clutch use and you could be near the end. Once it gets on the verge it is easy to tell through certain driving techniques, but until then it's hard to tell. So, it would not be a horrible idea to do it now if the risk of failure during the summer is totally unacceptable. Personally, I'd shop now for what I wanted and order the parts to keep on hand when the time comes along naturally. (For example, it can take months to get the Dali feather light combo.)

As for the syncros, I wouldn't even consider messing with those unless you have good reason to suspect one or more. They can last indefinitely if never taxed. The first to go is almost always the one into 2nd gear. You can test them quite easily with downshifts at appropriate speeds. I don't have time to detail that here at the moment, but they should be fine unless they were brutalized.

Perhaps you can find another winter project. I've got a 3.0 - 3.2 engine swap to do if you want some real fun!


[This message has been edited by sjs (edited 29 October 2002).]

 

[Larry Bastanza]

mmm....

40K miles and babied. I am thinking also there is really no need to tear it down at this point, unless you really could not deal with it during the "usable" months.

In regard to doing it in the garage, I had a chance to spend a day with Mark Basch doing a clutch a while ago. We were doing it with a lift and a transmission jack. This is a luxury I do not have. I mentioned to Mark that when it came time to do this for myself I would do it in my garage with a few floor jacks.

His response: "Man you have a lot of balls to do it that way!"

I have done many clutch jobs on the floor, since I do not have a lift. I cannot advise you since I have not done the NSX yet. I am thinking you will just need to get the car high enough on stands to get clearance to slide the trans out.

When I do this I usually make a small wooden dolly to roll out the trans. I construct it in a way that the dolly actually gets mounted on the floor jack, so when I lower the jack I can remove it from under the dolly, and roll the trans out easily.

Again this is all speculative, since I have not done it yet. If in the future you hear loud screaming from a garage in Warwick, NY, you will have your answer

.

I would be very interesting in hearing from folks that have done this on stands. DanO, Matt, Steve??

HTH,
LarryB

[This message has been edited by Larry Bastanza (edited 30 October 2002).]

 

[Markbert]

Thanks for the help guys!

Originally posted by sjs:
Or, the person who babied it may not have known correct clutch use and you could be near the end. Once it gets on the verge it is easy to tell through certain driving techniques, but until then it's hard to tell...

This is more of less what I am afraid of. I know the car was never aggressively at all, but fear it may have been driven without rev-matching, with slow clutch letout on startup, etc..

Originally posted by sjs:
As for the syncros, I wouldn't even consider messing with those unless you have good reason to suspect one or more. They can last indefinitely if never taxed. The first to go is almost always the one into 2nd gear.

Same story as the clutch here. I know the car was not driven aggressively, but I doubt rev-matching was perfect (or possibly even attempted) on 1-2 shifts. The first two owners were sports car enthusiasts (and NSX enthusiasts), but didn't seem to be driving enthusiasts or into the NSX community deeply. The weather is getting colder (my first winter with the NSX) and I cannot tell if the notchiness is a byproduct of the cold weather or of worn synchros. The thought process here was more of less 'as long as you have the clutch out you might as well make sure everything is perfect'. If buying/rebuilding/installing a 6 speed weren't so expensive, this debate would be over.

Originally posted by sjs:
Perhaps you can find another winter project. I've got a 3.0 - 3.2 engine swap to do if you want some real fun!

I am about 4 hours from St. Louis (Jackson, TN). I may take you up on that if its over a weekend. I am always up for learning.

Originally posted by Larry Bastanza:
I have done many clutch jobs on the floor, since I do not have a lift. I cannot advise you since I have not done the NSX yet. I am thinking you will just need to get the car high enough on stands to get clearance to slide the trans out.

When I do this I usually make a small wooden dolly to roll out the trans. I construct it in a way that the dolly actually gets mounted on the floor jack, so when I lower the jack I can remove it from under the dolly, and roll the trans out easily.!

This is more or less the plan, although I don't know if I can get the car up high enough this way. If not, I can always keep building the jack stands/Jack up a few inches at a time with a wooded or brick base. I am hoping it doesn't come to that.

Originally posted by Larry Bastanza:
Again this is all speculative, since I have not done it yet. If in the future you hear loud screaming from a garage in Warwick, NY, you will have your answer .

I would be very interesting in hearing from folks that have done this on stands. DanO, Matt, Steve??.!

Too bad I don't live in NE New Jersey anymore. I think I am brave/stupid enough to try it with someone else's assistance or experience to guide me. However, by myself and with no one's experiences to build on might make me nervous enough to haul it to Barn Man in Nashville.

Anyone?

Edit: damn this is a long post

[This message has been edited by Markbert (edited 30 October 2002).]

 

[Larry Bastanza]

Where were you in NE New Jersey??

I am definately "stupid" enough to try it

LOL!!!!!!!!!!!!!!!!

LarryB

 

[Lud]

I would never do "precautionary" replacement on clutch or synchros... Wait for them to start dying.


I doubt I would attempt do DIY any tranny work, but if I had several months where I didn't plan to drive the car, a way to lift the car up fairly high, a friend who was mechanically inclined to help, and a LOT of free time, it might be fun and certainly educational.

 

[DanO]

Originally posted by Markbert:
This is more or less the plan, although I don't know if I can get the car up high enough this way. If not, I can always keep building the jack stands/Jack up a few inches at a time with a wooded or brick base. I am hoping it doesn't come to that.

Getting the trans in/out without a safety risk would be my biggest concern. It’s one thing if the DIY project screws up the trans, it’s a whole different story if the DIY project screws up the DIYer.

I think we first need to find out how high off the ground the car needs to be to pull the trans out. Then we need to find out how to safely lift and stabilize the car that high. Everything else is fun!

Anyone have a tape measure? <g>

 

[Markbert]

Originally posted by Larry Bastanza:
Where were you in NE New Jersey??

I am definately "stupid" enough to try it

LOL!!!!!!!!!!!!!!!!

LarryB

I worked at Merck Medco (now Medco Health) in Franklin Lakes until April. (north of Paramus on Rt. 208, about 5 miles south of the NY throughway west of Palisades Center). I liked the area, but decided to get out when Merck annouced they were going to spin off Medco. I still get up to visit friends. How far are you from there?

 

[Larry Bastanza]

Mark,

I was born and raised in Bergen County (Maywood, NJ). I live in New York State now and work for Minolta in Ramsey, NJ.

Actually pretty close. Please e-mail me if you are coming into the area. Small world

Thanks,
LarryB

 

[Markbert]

Originally posted by Larry Bastanza:
Please e-mail me if you are coming into the area. Small world

Very small world! YGM, and I'll probably be up sometime this winter for a weekend at the minimum.

 

[sjs]

I've got a complete drive train on the floor, so I'll measure it later, but I estimated it once before and figured the trans alone would not be a problem with large stands. Seems to me it slides out the side after pulling the left rear suspension and such. That’s a pretty tall whole.

I planned on buying one of those ATV/cycle jacks to use as a tranny jack/trolley. They're cheap from Sam's or equivalent.

 

[sjs]

The tranny is only about 18 inches tall, then you need to add enough for the jack/trolley under it. But there is quite a bit of clearance even before you start jacking up the car, so stands of 18 inches might be plenty.

 

[Markbert]

Originally posted by sjs:
The tranny is only about 18 inches tall, then you need to add enough for the jack/trolley under it. But there is quite a bit of clearance even before you start jacking up the car, so stands of 18 inches might be plenty.

Excellent, thanks for the info - that gives me a little hope! FYI, there is a decently priced tranny jack on harborfreight.com - about $60 if memory serves.

As for my dilemma: I need to measure everything, but if I can get it to work I am starting to see the logic in not replacing synchros just yet(took it for a drive tonight and it felt good). However, common sense apparently has not gotten me overly far as I have started to consider a possible used 6 speed tranny.

Depending on how the numbers add up, I can see buying the 6 speed, refurbishing it, replacing the clutch/wheel and selling the 5 speed. I am not sure that is in the budget, or if I can even do it, or if I am willing to deviate from OEM. I am a 120mi from a decent NSX tech, so that raises the stakes a bit, we'll see.

I stay with OEM, I am thinking the clutch is still a realistic possibility. There is a twin disc 91-96 w/o bearing on Ebay that might be worth a shot - its about the only thing mechanically left on the car to replace.

That much I am fairly certain I can do. Cross your fingers.

 

[sjs]

If you want to start saving your pennies, I'll be selling a 6-spd with the CT 4.55 R&P at some point in the future. It's in a car now and had ~8k miles on it since brand new. It will come out when I do the 3.2 swap along with the stock 6-spd attached to it. For me, the 4.55 is just too short for a boosted car.

 

[Markbert]

Originally posted by sjs:
...I'll be selling a 6-spd with the CT 4.55 R&P at some point in the future...the 4.55 is just too short for a boosted car.

I am definitely interested in the 6 speed. Please PM me when you get ready to make the swap. As for the 4.55 R&P, I think stock or 4.23 is as closely geared as I am comfortable with. Surely someone around here does not agree with me on that, which would work out wonderfully from a sales perspective

 

[CityofAngels]

14" is what I set my jack stands in order to get my tranny out.

If your synchros operate fine and your clutch doesn't slip, then you have no need to replace anything.

And not to be rude, but if you have never worked on a motor before, get some experience with something smaller and less complicated like a lawn mower or motorcycle engine.

Easier to get into trouble than to get out of it!

 

[Markbert]

Originally posted by CityofAngels:
14" is what I set my jack stands in order to get my tranny out
...<snip>...
if you have never worked on a motor before, get some experience with something smaller and less complicated like a lawn mower or motorcycle engine.

Easier to get into trouble than to get out of it!

Agreed, and definitely good advice!

However, I don't own a lawnmower or a motorcyle and I do have a few people in town that I can call on for non-NSX specific automotive knowledge. I am hoping that will work. If not, I'll trailer the car to Barney in Nashville as a last resort.

As an update, I think I have about decided on using the Exedy clutch when the time comes. I am also tentatively planning on swapping out the tranny at the same time if I can find a decent deal on a used six speed before the OEM clutch croaks.

Mark

(edit because the "spell check" button and the "submit now" button are two completely different entities)

[This message has been edited by Markbert (edited 14 November 2002).]