Help Changing 308 Timing Belts

While you're in there, take a good look at the cam drive pulley outer bearings.

 

Word of advice-------------- while the cam covers are off purchase or fabricate some backing plates for the covers---------------- don't ask why I know but THINGS have a way of falling into the web of pulleys and belts offering a potential massive failure. Lost

 

His car would already have those. QVs came with them.

In response to the original request, it's not a hard thing to do yourself if you have any mechcanical experience at all. Lot of write-ups on how to do it are available. Just print one out and follow the directions. I did mine myself this winter and it wasn't hard.

 

If your cam timing is correct, just lock your cams using some non-marking device. I bought Verell's (found on here) wooden cam locks. Then mark the old belts and corresponding teeth on the pulleys, transfer those marks to the new belts, loosen the tensioner, replace belt at the EXACT same teeth location, install new tensioner, done..


Greg

 

What about turning the engine over a couple of turns before locking tensioners.....

 

Personally... and this is strictly a personal opinion, not official workshop manual speaking ... I had a bad experience doing this with the 308. We were doing the cam timing and setting the tensioner, and one of the cams jumped the belt with the tensioner loose. Fortunately, the engine was out of the car, so all we lost was some time resetting everything (which was a fair amount of work).

I am currently doing the 328 belts right now with the engine in, and I'm not turning it over with the tensioners loose. We are locking them down, turning the engine a couple of times, back to TDC, loosen, reset them, tighten and turn it over a couple of times again. YMMV, but this method works for me. (All disclaimers incorporated by reference... )

 

It seems to me the belt should have the least amount of slack in it with the tensioners unlocked. But if you happened to turn the engine in the wrong direction, all bets are off.

Chacun a son gout.

 

I have done this on my 328 and have always done it on Fiat/Lancia twin-cams as recommended. I think the key is to turn the engine over slowly and smoothly (no jerky movements). Having said that, a key to turning over smoothly would be having all spark plugs removed so you're not fighting the build-up (and release) of compression.

 

That's what I do - remove spark plugs, raise rear of vehicle, put the transmission in 5th gear, and turn the rear wheels slowly with a pry bar. I use this method because I don't have a socket large enough to turn the crank pulley directly.

 

Here are some parts of a video I'm working on....

http://www.youtube.com/watch?v=VBgJfO7vwYk

http://www.youtube.com/watch?v=YG01Rn3F-Uo

http://www.youtube.com/watch?v=M5OegP_XE2E

 

+1 my 84 QV has it see pics below.

+1 Pic shows the wooden locking tool I made, very simple cheap, and effective. I'm making another one out of a teflon.

I don't understand why the belt would jump, I've replace t-belt many time, and once installed, I always rotate the motor several times for the belt to set in before I lock the tensioner bearing in place. I believe once the belt is installed it shouldn't jump just make sure you mark all the pulleys with a white out or something before removing the old belt.

+1
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Yup, had plugs out, cams and belts marked, etc., turning it nice and slow with a long breaker bar and socket, and ka-sproing, the intake cam jumped a tooth. Go figure.

 

:-(

weak spring or gummed-up spring mechanism? Having the valve covers off and then squirting each valve shim would probably help reduce turning resistance a fair bit.

 

Charles,

I need to do mine to, lets get together and do both!

Want to do them in Jax or at the lake House?

Give me a call

Doug

 

I just got a piece of teflon to make my cam gear locks. Now I get to play machinest, Does anyone know what diameter the gears are?

 

I just use Vise grips if it's QV. Dealers use the same method, seen it done on 348 and 355's as well. Just requires a "little" pressure to hold them.

 

Not all the QVs came with the backing plates. I own a mid-year 1984 build with no backing plates. And am certain that except for what I've done to the car (Tubi, QA1s, that sort of thing), the car is as it left the factory.

Phil

 

Phil, you sure your 84 QV originally didn't came with the backing plate?
It's funny because my 84 QV built date was 12/83 and it has one.