Automotive repair question ?

[TopCatGr58]

Hey folks,

Okay, have a PITA job to do on my SUV! Timing belt change on a 2004 Xterra 3.3L V6. I have a service manual, and this engine doesn't use an auto timing belt tensioner....it uses a staticly set tensioner that they say does not need resetting once it's set for the life of the belt...~ 100K miles which it is now a little overdue, hence my need to chnage it.

However, the book says that I need to apply 22 lbs of tension/force against the belt between the 2 cam sprockets and measure the amount of deflection, should be ~0.50 inches. If it's more or less, I have to readjust the tensioner position.

MY question is HOW do I apply this measured amount of force? I don't have a fancy tool, or even a pull force gauge that I could rig up to the belt!
I have some weights that I use for lifting, I could place a 20 lb weight on the belt since a 20 lb weight is 20 lbs of downforce.

Any other suggestions?

T.C.

[petejw]

hey tc, could u get hold of a set of weight scales
that u measure the weight of fish with?
personally i wouldnt worry so much about the
weight of force or tension, using ur hand to move the belt, just make sure u have the deflection set correctly.

[petejw]

something similar to this

http://www.ebay.com.au/itm/FISHING-SCALES-BERKLEY-DIGITAL-SCALES-30LB-/221046296186?pt=AU_Accessories_Tackle&hash=item337762ce7a

[jwhughes3]

just set deflection

I think the tensioner weight will take care of itself if you have the deflection set to correct amount.

John

[Tat2demon]

A fish scale?

[DGXSER]

Yep, the kind you see in the open air fish markets where they sell the whole fish by the pound. We use them on projects to check the amount of force required to open a door to a building. There are code requirements for it, to make sure elderly and disabled can open the door.

[TopCatGr58]

Well,

I dove into it this AM ~9:30, ran into a couple of annoying setbacks. First, trying to get the crankshaft pulley bolt loose! It's kinda hard to break 8 years of heat/rust/tension....and I didn't have a strap wrench big enough to be able to grab the pulley. My chain strap wrench was 18", I would have needed ~22-24", nobody had one. Went to NAPA, they had an oil filter fiber strap wrench that fit, but took some doing to get it to grab and hold the pulley, but finally got it broken.

THEN, took a while to get the actual pulley off of the crankshaft. PB-blaster, and after trying some prybars behind the pulleys...per the manual...I finally tried the 3 jaw puller GENTLY....the manual said not to due to possible damage to the pulley....but I was finally successful!

It was a bit more involved than my swmbo's car. I had to drain the cooling system, disconnect the tranny cooling lines, pull the radiator, fan, shroud, move the electrical harness and ~10 connectors, PVC piping and such, as well as the 3 separate drive belts, brackets and such. Then the Timing belt covers.

I was surprised to find how much SLACK was in the belt, but then again with 100K miles, what did I expect! Another surprise was after putting the new belt on with the crank and cams at the proper timing marks/positions. The manual then said to rotate the crank 2 times and recheck the timing marks. I was expecting the original new belt white alignment marks to line up, but they didn't! The cam and crank marks were still aligned, but it took me a while to realize that they were only worried about the # of belt notches between the crank and the first and then second cam sprocket....but not on the slack/tensioner portion, and so the belt marks were not going to line up, at least not for the first several crank revs. I set the tension slack by hand trying not to get it too tight.

While I was in there, seeing how much it took to get to this point, I decided to go ahead and replace the water pump....putting some tension on the fan mount as I spun it, I thought I could feel a little grinding/stiffness in the bearing....not so with the new one.....didn't want to have to go thru all of this in the possible near future to replace the water pump!

With the newer aluminum radiator and engine components, I was surprised to still see clear blue ANTIFREEZE when I drained the system...not contaminated with RUST and such! Anyways, some 8+ hours later I was able to fire it up, and it fired up just fine, no leaks, and no nuts/bolts left over! :P

I'm sure someone will point out that I probably should have replaced the THERMOSTAT as well, but it doesn't require as much tear down to get access to it, so I left it in there for now..plus was worried about getting what I had to get done in time. So....I had to spend bit more $$ that planned for the extra strap wrench, and spent many more hours as well, but I did save myself close to $1k of actual mech. fees If I had taken it to the dealer!

Now...where did I put the Motrin?
T.C.

[GLoweVA]

Glad you got it done. However if you hadn't then you'd have an excuse to ride your bike to work in the morning.

[jwhughes3]

Water pump

Glad u made the call. ALWAYS replace he water pump when you replace the drive belt tensioner or you will be back n there again soon. DAMHIKIJK and I didnt learn this lesson the FIRST time

John

[petejw]

how did u go with setting the tension of the belt?

[jjz28]

I have a 92 svx with a 3.3 boxer H motor. I didnt even want to attempt the timing belt so i called a shop and they done the timing belt and water pump for $150. If the belt and everything would have been in place, i would have did it myself but it had broke so nothing was lined up. I figured a half of days work was worth it to get it done without me getting dirty. They replaced the water pump too, you always do that with the timing belt. Actually that is what caused the belt to break was the timing pump locked up.

[WMarshy]

I have a 92 svx with a 3.3 boxer H motor. I didnt even want to attempt the timing belt so i called a shop and they done the timing belt and water pump for $150. If the belt and everything would have been in place, i would have did it myself but it had broke so nothing was lined up. I figured a half of days work was worth it to get it done without me getting dirty. They replaced the water pump too, you always do that with the timing belt. Actually that is what caused the belt to break was the timing pump locked up.

That must be easy to work on because that is really cheap! I will be doing a timing belt/water pump on my wifes car in the near future as all the shops want around $800 for the work including parts!

[natemoen]

Heck It was around $130 just for parts when I changed the timing belt, water pump, and the accessory belts on my wifes car earlier this year.

[slow mo]

just got rid of my 2002 xTerra started using a lot of gas ,,90$ to fill for 290 kms.. great truck but gas guzzler to me ,,ride safe ,,,slow mo!

[TopCatGr58]

how did u go with setting the tension of the belt?

Hey Pete,

I first took a rubber handled hammer, then placed a 10 lb weight on top of it and the handle on the belt, and observed the amount of deflection, then used my bare hand to make the same amount of deflection to get a "FEEL" for about 20 lbs of pressure...then adjusted the tensioner a few times till I got it just right! It's a shame they make it so hard to get to the adjuster, otherwise I'd check and set it at like 50k or so. I still can't believe they don't use an automatic or spring controlled one? There is a spring on the tensioner, but it's still LOCKED in place one you set the amount of tension! I guess they calculated that too much SPRING tension keeping it tight might cause the belt to stretch prematurely reducing the 100k range/durabilty it currently has!?

Swmbo's V-6 uses a spring maintaining tensioner, but the belt is only rated for 60K miles...but much easier to get to relatively speaking vs. my Xterra! Yeah SlowMo....it gets about 19 mpg, but it's paid for, working just fine otherwise, and provides me a decent cage of protection against these IDIOT cage drivers around here in my 22mile one way each way daily commute!

Yeah George, I would have had to ride my bike, but then I'd not get BREAKFAST!
T.C.