Can you get to the 19mm bolt to loosen the tensioner without taking off the fan clutch, etc?

I have a loose belt which probably means a bad tensioner... but I want to tighten the belt once to see if I will be ok.

This is on my son's 1989 300e.

I should have put in a new tensioner when I did the water pump...

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

you can try, but I'm sure it would be easier to just take the fan blade off. Realistically you are only talking about another 5 minutes tops on either end of the task you are undertaking, esp. if you have a fan shroud that comes in 2 pieces and not just 1.

__________________
87 300E
202k on the clock

You can loosen the tensioner bolt without removing the fan. You will just have to remove the clips that hold the fan shroud and move it out of the way.

__________________
1986 300E (3/2002) Rear ended and totaled (10/2009)
2000 Xterra (5/2000)
1992 400E (11/2009) -Sold
1986 300E (12/2009) - Sold
2004 E500 Wagon (6/2013) - Sold

Well we need a new tensioner. It just won't tighten. Is it necessary to get a new tightening rod bolt as well?

Tensioner is on order

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

What state is the malfunctioning tensioner in ? If it is in a state that it is loose and wont let the regular size belt on, I may have an easier solution. Get a longer belt. The belt I have used and works great is Dayco Poly Cog, 5060915, 6PK2325. What you do is loosen the top bolt on the alternator, remove the bottom bolt, put the belt on and push the alternator down in place, and finally insert and tighten the bottom bolt, and tighten top bolt too. I could have also used 2320 length but this one is not available, only Bando makes it and only comes stock on one american car. But this one works fine so far on my 87, 260E, and I can tell from the A/C working great.

__________________
Saumil S. Patel

It would be foolish not to replace the rod and bolt while you are there. You may find that your real problem is that rod bolt is stripped.

__________________
2012 E350
2006 Callaway SC560

There is no need to replace the nut and rod. Unless you break it, they are just fine.

__________________
1986 300E (3/2002) Rear ended and totaled (10/2009)
2000 Xterra (5/2000)
1992 400E (11/2009) -Sold
1986 300E (12/2009) - Sold
2004 E500 Wagon (6/2013) - Sold

Lee,

You can inspect the old/new tensioners by clamping them in a vice and deflecting them 30 degrees. Bad ones stay there...

If you look at the flats on the aluminum shaft of the old one, you will find that they are worn, and maybe also those on the steel adjusting bolt plate, but much less so. The problem is one small section on the shaft.

One trick that got me home and lasted quite a while is to reverse the order of the bolt plate and the spacer when you reinstall. (You might need to flip the plate over, but it is symmetrical.) Reversing the installation order will put the plate on an unworn section of the shaft. It will wear again, as that aluminum is a dumb choice of materials for the shaft, but this will give it a second life...

Gerry

Even though my tensioner failed, the car seemed to drive fine, except for the brief belt screech at startup. I'm guessing this is the fail safe function of the tensioner shock that keeps some tension on the belt.

glenmore
1991 300CE
2000 C280
1990 LS400