850 140k Major Maintenance

[rspi]

I didn't change my belt today but when I looked at it, the belt was tracking to the rear, closer to the motor. Looks like it's on the back edge of the rollers and cams. The water pump has an edge on the back of it's gears and the belt may be against that.

I'll likely change it within the next few days, probably Tuesday. The cam marks are real hard to see. Someone just put a mark on the cams and belt cover and replaced it. I think I'm going to find TDC and re-file cam timing marks.

[cn90]

For a long time, I could not figure out why the WP lasts 140K-200K (in most cars, WP dies around 80K-100K).
Also the TB pulleys last some 120K or more.

But the serp.belt pulleys make noise around 100K....

It is all in engineering. If you look at the pic I posted previously (posted again here for clarity).
For every engine revolution, each component may spin once or twice, or more...

The TB Compartment:
- CRANK Pulley for TB: it has teeth and its diameter is similar to the diameter of the WP and of the tensioner/idle pulleys.
So for every 1 revolution of engine crank, the WP/tensioner/idle pulleys turn once.
In other words, for every 1 Million of engine cranks, the WP/TB tensioner/TB idle pulleys turn 1 Million times.


The Serpentine Belt Compartment:
- CRANK Pulley for Serp Belt: it is smooth and has a larger diameter, about 2.0x or 2.5x that of the tensioner/idler pulleys.
So for every 1 revolution of engine crank pulley, the tensioner/idle pulleys turn twice (or more).
In other words, for every 1 Million of engine cranks, the Serp Belt tensioner/idle pulleys turn 2 Million times (or more).


Here is the TB compartment pic:
https://www.matthewsvolvosite.com/forums ... &mode=view

[jalwlb]

These directions were very helpful and everything went smoothly. I was even able to remove the belt without cutting it by twisting it at just the right moment before pulling down. As someone else said, the hardest thing was removing the torx 45. My socket driver and torx socket fit in that narrow space, but I was nervous for a while I was going to strip the screw head. It was the only tight bolt in the disassembly. I even thought to myself, "these bolts aren't that tight." After removing and replacing the water pump, I took a break to run some errands. Upon return I read in step 21 to torque the water pump bolts to 25 lb/ft which I attempted until I broke a bolt. I found a second one broken while removing the pump again.

Am I only one who attempted to torque these bolts this tightly? I regret the run for errands in the middle of this project because I might have kept in mind that thought, "these bolts aren't that tight." A 1/4" bolt extractor is too big to grab the 6mm studs because I suspect the bolt stretched a bit before breaking. I've tried miniature vise grips and a keyless drill chuck to grab these studs and turn them loose but no luck. Any tips that don't involve the phrase, "pull the engine", would be greatly appreciated.

[Ozark Lee]

Upon return I read in step 21 to torque the water pump bolts to 25 lb/ft which I attempted until I broke a bolt. I found a second one broken while removing the pump again.

Wow, that is a huge mistake on my part, the torque spec is actually 15 lb/ft. That is very near the lower limit of most torque wrenches which is often not accurate anyway. Correction made to the writeup.

Where did the bolts break and how much of the bolts are exposed in front of the block? if you have enough to grab a hold of with vice grips then soaking them overnight with PB Blaster might just do the trick for you.

...Lee

[jalwlb]

It never occurred to me to try PB Blaster on studs that have been in the block only a day or two (now two weeks). They can't be tight so much as really sticky with the thread sealant that comes on those bolts. I'll certainly give that a try. I have a 1/8 " sticking out on one and 3/16" on the other.

Thanks for the quick response!

[cn90]

Does anyone have Cam Sprocket Bolt Torque?

[rspi]

I'm pretty sure they are 15 in/lbs. (Yes just confirmed on iPd's website on their Cam Timing Instructions).

[futureboycolin]

Lee, I can't thank you enough for the write up. I just installed the blue Gates racing belt last night. I did all my pulleys and the water pump as well. Your info was invaluable!

A couple things that made my life easier:

I removed the ECU and ECT, as well as the top of the ECU box, the housing, and the air hoses attached to the front and rear. That made a HUGE difference in the amount of clearance I had. I also removed the Serp tensioner assembly after it was locked.

I still had a helluva time installing the tensioner under the tensioner roller. I had to fashion a hook from a wire hanger, pull it up and loop the hook around the receiver for the bolt that holds the timing cover on. I got the tensioner in without a hitch after that, unfortunately the plastic receiver piece snapped off. Gonna go back in and superglue it at some point. I also had major difficulties with the plastic retainer sleeve. That thing was ridiculous hard to pop in with limited clearance.

Once again, thanks man, invaluable info!! Saved me $900, and the car's driving like a dream.

[skr]

Just replaced my whole timing belt assembly and water pump. First time, took 5 hours. My biggest problem, like many have noted was removing the T-45 on the tensioner roller. I probably spent a good hour trying to work around the serpentine belt tensioner roller from a number of odd angles. Eventually, I removed the serpentine belt tensioner and got it moving using Lee's box-end wrench+bit+pipe method.

The extra space created by removing the serp belt tensioner makes it a helluva lot easier so I would definitely suggest it.

Thanks for the write-up, Lee!

[Leadsled850]

I have a few questions on this change. When I removed front cover on timing belt, I noticed side of belt had been rubbing on the cover. Upon further inspection, I found that engine side lower cover had been pushing against belt forcing it outward towards front cover. In attempt to flex lower engine side cover away from the belt I broke it. How do you remove this lower engine side timing cover? Also, I noticed my pulley does not sit on tensioner arm. Is this normal? Iwill attach some pics, thanks for the help...