Steve_P

iTrader: (5)

Ok, I've searched and I've found a few posts on this but no great solution.

I've done 6+ timing belts on the 4G63 in DSMs so I am familiar with the procedure. I'm doing it for the first time on my Evo IX. On the DSM, the tensioner pulley is installed "reverse" from the Evo- meaning the two holes for the tensioner tool are on the top instead of the bottom. Does anyone know why this was changed? The pulley is the same, or essentially the same.

The reason I ask is that the DSM tensioner pulley was easier to set to get the correct protrusion on the tensioner cylinder pin. When you tightened the bolt on the DSM pulley, it would move towards the belt and the belt would stop it from rotating. On the evo, when you tighten the bolt, the pulley moves away from the belt and I keep getting excessive extension on the cylinder. I've tried holding the pulley with the special pin tool but it still moves.

I've only tried it twice but I'm used to getting it right the first time.

So, what are the tricks to keep the pulley from rotating when tightening it?

Has anyone installed the pulley the way the DSMs were oriented? I'm wondering why this was changed.

Thanks

LetsGetThisDone

iTrader: (1)

I'm guessing they changed it because for the pulley to allow the belt to loosen, it pivots in the same direction as tightening the bolt, so it's harder for it to come loose.


I use the Jay's racing tensioner pulley tool. Hold it with an 8mm boxed end wrench while I torque the bolt.


I also set the timing belt tension to where you can pull the grenade pin out, and reinsert it after rotating the engine a few times.

Steve_P

iTrader: (5)

Thanks. That's the only reason I could come up with on the orientation swap but it still doesn't really make sense. IIRC the balance belt tensioner pulley installs the same way it used to and that's to "loosen" the bolt under belt load. Anyway, I'll try again this weekend and update.

The protrusion spec on the cylinder rod is .15-.18. I'll see what the value is where the grenade pin comes out

barneyb

I've also done both and the pulleys looked and operated the same for me. I have an 8. Are you using an OEM belt?

The loose grenade pin technique was developed on and for DSM's. Its been around a long time.

Steve_P

iTrader: (5)

yes, OEM belts and pulleys.

Ok, I checked and the grenade pin method gives .15 protrusion. The spec is .15-.18 so that works.

This is what I ended up doing: I used the tensioner cylinder release threaded rod tool to set the tensioner protrusion at .16, measuring with a drill bit. (this also goes back to the DSM days) I tensioned/rotated the pulley using the pin tool and positioned the ratchet handle on the crankshaft bolt to keep tension on the pulley. So far this is what I tried before. This next step was the key for me in stopping the pulley from rotating, and belt loosening, when tightening the pulley bolt. I took some tapered wooden door shims that I had, cut them shorter, and jammed two between the pulley and the water pump. I pushed them so the wedge action put force on the pulley and they stayed in place on their own. Then I tightened the pulley, removed the shims... checked the gap and it was the same at .16.

barneyb

As best I recall, in 1992 the service manual required the use of a 1/4" torque wrench and the special tool that fits the pulley. You were supposed to apply about 24 inch pounds of torque (I don't know why) and then measure the protrusion of the tensioner plunger. I actually made a go-no-go gauge. If one side fit it was too loose and if the other side didn't fit it was too tight. All this while lying on your back under the car and not being able to see much.

Also, there was something about the threaded rod that was the other tool in the kit or maybe the engine that would cause the rod to get stuck in the engine, either stripped out or seized, and people were writing the forum asking for help in that predicament.

The method still works but adjusting until the grenade is loose is so much easier.

Steve_P

iTrader: (5)

yes, the torque wrench method is in the DSM service manual- I think it is even in the Evo manual. This was how you were supposed to get to the spec'd .15-.18 protrusion. But the forum method drill bit (or your go/no go gauge) method works great. Is there even room for a torque wrench on an Evo?

People were initially using the DSM battery hold down bolt to depress the tensioner and it would strip. If you use a class 8.8 threaded rod it works fine. I made one with some threaded rod from McMaster, grind off the first half inch or so of threads down to the minor diameter and then add a couple of nuts on the other end. I will say that it was very helpful having the tool to lock the cams together since I have a IX. I bought one on ebay from K-motor performance and it is very precisely machined; you have to have the cams perfect to fit it in. So thumbs up for that.

I did all the DSM changes with only the threaded rod tool and wrenches zip tied together for the cams but IMO for the Evo IX it's handy to have all the tools, especially if you're working alone.