Timing Belt

[nsx4fun]

The DIY section doesn't have a Timing Belt replacement description. Has anyone here done this themselves? How hard of a job is it? How long does it take? And how much does the Timing Belt cost? My car is a '92 with almost 35K miles, but at 10 years on the stock belt, I figure it may be prudent to change it, rather than wait for the mileage.

Fritz

 

[Larry Bastanza]

Fritz,

Yes, I have. And although it was quite a challange the first time, I would not hesitiate to do it again. If you do a full 90K service complete it would be about 10 hours, based on my experience. I will say up front it actually was about 20 hours for me the first time, for many reasons, but the paramount reason was just paying my dues the "first time".

I am in the process of a write up, but it is too premature yet to post. If you are serious about it private me and we can discuss it.

I am hoping maybe Barnman and/or MarkB may see this and comment about the time. They probably do it in 4-5 hours!

But.... This does have it's risk elements. If you screw up (I thought I did, but actually just scared myself!!!) it will be expensive. The learning curve is steep on this procedure.

I would be happy to talk about it with you.

A word about costs: I had about an $850 parts bill. Belt was $127, Water Pump $150, add it all the gaskets, spark plugs, fuel filter, etc. Remember if you are going in there, and it is a lot of work, do it all once!

Oh, mine is a 1991, it had 30K when I did it in the March 2002.

HTH
LarryB



[This message has been edited by Larry Bastanza (edited 18 July 2002).]

 

[DanO]

It's a tough DIY project to say the least, but if you have lots of car DIY experience and really enjoy working on the NSX and have the time, then it may be worth considering. Like Larry said, the costs of screwing up are high (read: www.danoland.com/nsxgarage/bent/index.htm) but once you do it once and figure it out, it's really not that difficult...but it's still a pain.

.02

DanO

P.S. Larry let me know when you're done with the DIY, I'd like to see it!

 

[Larry Bastanza]

Hey DanO,

Actually I was hoping you would proof it with me

.

I had some special pins machined to hold the cams. They are 6mm shafts with 5mm ends. They fit tight in the cam cover but a little loose on the cam hole. It ends up that you only can us them on the front intake and rear exhaust. I came up with a totally fool proof way to set the cams properly. But since I only did my engine, I need to see if it works on another exactly like mine. Mark B. has the pins now, and I just need to get a hold of him, since he was going to try this technique and see if it panned out as a general method.

I'll let you know what I find out.

Thanks,
LarryB

 

[anvil]

Did you replace the tensioner spring and pulley?

anvil

 

[Larry Bastanza]

anvil,

No, I didn't. With 30K miles and the fact it was in perfect condition, I saw no need to.

The other thing in the background of my decision was I did the timing belt on my Honda Accord at 95K, left the tensioner in. I did it again at 185K, then I replaced it. The fact is, it really was still OK at 185K.

The NSX tensioner pulley and spring looked and felt brand new at the time of the job.

LarryB

 

[DanO]

Originally posted by Larry Bastanza:
Hey DanO,
Actually I was hoping you would proof it with me

.
LarryB

That sounds like FUN!

A few tips that I picked up along the way were MarkB’s double-secret trick #2 to fix the flywheel by removing the little flywheel cover and wedging a #2 screwdriver in the flywheel teeth (knowing that trick would have saved my valves). I also like BarN MaN’s double-secret trick #53 to use an inspection mirror and a little yoga to sight between (through) the cam gears to the back of the head where, if you get it right, will see the timing marks just like it shows in the service manual. The other thing that is good to remember is when you get to the step in the service manual that says to rotate the cams 9 (or whatever) teeth clockwise to re-tension the t-belt, do exactly what it says. The first time I did it, I rotated the driveshaft gear, not the cam gears. Whoops. One more helpful tip is that when you’ve almost given up trying to remove the rear t-belt cover, go ahead and give up and have a beer. When you get back to it, it will come right out.

DanO

 

[Larry Bastanza]

DanO,

I actually purchased the crank tool and it was a breeze to get the crank bolt off and on again. Barney told me exactly how to do it and it was very easy. (You need a 3/4 inch breaker bar and 4" extension though, and a 3/4-1/2 reducer, since you need to use a 1/2 drive 19mm socket to fit inside the crank tool. (I got the tool since I have done many Accords with this type of tool before, actually I think the tool for the NSX will work on an Accord, but not visa-versa.

I also did the mirror thing, but if the pin idea works out as a constant for all engines, it requires no mirror at all. I will hold my opinion on that though!!

I re-read the service manual and actually I kind of did that as I installed the belt, in fact once I advanced the rear exhaust cam, installed the belt on it, I used a wrench to retard the cam until the belt was tight between the two rear cams, checked the marks, then easily just pulled the belt tensioner into position and locked it.

Then I did a 720 degree rotation on the crank and checked all the marks. Once OK, I rotated the crank to the blue mark on the crank pulley, loosened and retightened the tensioner, then buttoned it up.

LarryB

[This message has been edited by Larry Bastanza (edited 19 July 2002).]

 

[sjs]

I've done mine as well. It is not for beginners, but a competent and patient DIY wrench can do it. Don't start on it unless you can afford to have it down longer than expected.

To remove the crank pulley I bought a very large nut that fit inside the hex shaped recess in the pulley. I then used a large crescent wrench to hold that (the handle end stopped against the floor) while I used a socked and short extension through the center to break the bolt loose. (Actually, I had to grind down the nut somewhat to make it fit.)

Basically I would discourage you if your only reason is to save money, but if you really like such stuff and are pretty confident, give it a try.


[This message has been edited by sjs (edited 20 July 2002).]

 

[nsx4fun]

Am i mechanically inclined? My roll away is taller than me. Last summer I put a used japanese motor from Atarco into my wife's CRX, her old one had 225K miles on it. Obviously with the engine out of the car replacing that timing belt was a piece of cake. I have also rebuilt my Honda CB750 several times. So things like cam timing I understand very well as well as plastigaging new bearings etc. So if I can save $600 or so and spend one to two days getting dirty, cussing when I lose skin off my knuckles, taking that stop for a beer to relax to find the stuck cover now slides right off, I might. I would be interested in reading the preliminary DIY, and consulting my service manual to aid in my decision making process.

If you want, please send your preliminary DIY to [email protected]

Thanks, Fritz

 

[sjs]

It sounds like you qualify, but you didn't give us your credentials at first. You could get by with the factory manual alone (I did) but if you can wait for Larry's write-up, that would probably save some of the cussing.