Timing Belt Tension

[d didit]

Does anyone know the correct lbs of tension for the S4 timing belt. I check my tension and it read 110 lbs at TDC. When I rotate it 90 deg it reads 100 lbs. I am not sure which I should go by and in addition, what is the correct value using the kricket gauge. I got 100 lbs because this was the value I had when I originally replaced the belt and having taken a measurment before proceeding.

Also, I am having the hardest time trying out how to correctly tension the alternator. I pry between the mount and alternator but this does not seem to give me enough tension.

A word of advice! When you change your timing belt, make sure you replace your water pump at the same time. I got mine at JAE. I had to do it all over because my pump started leaking right at the SEMA show while it was on display. The remedy, I shoved a rag to collect all the coolant leaking before it hit the earth. Heh Heh. I ordered my pump and installed it in about 4 hours total. All is well and now I have peace of mind.

Dindo/ 95 S4

[Skerd]

This is per page 19 of section EF of the repair manual. It says you need a "Burroughs gauge" and that the correct belt tension is 95 units on the gauge. A Lotus dealer will probably let you borrow their gauge. I remember reading somewhere this does translate to roughly 95lb.ft. Cannot help on the others.

[lotusguy]

Skerd said: This is per page 19 of section EF of the repair manual. It says you need a "Burroughs gauge" and that the correct belt tension is 95 units on the gauge. A Lotus dealer will probably let you borrow their gauge. I remember reading somewhere this does translate to roughly 95lb.ft. Cannot help on the others.

Dindo,
Using a kricket gauge, your reading should be 50-55 lbs. the Lotus Burroughs gauge merely has a single index on it which says 95 units. I have a burroughs gauge which is indexed in lbs. and the Lotus gauge does indeed translate to 95lbs. But in repeated tests using a kricket gauge on a known properly tensioned belt, the reading consistently read 50-55lbs.

If yours reads more than that, then your belt is overtightened and needs to be loosened. If you have driven the car any number of miles since tightening to that tension, you should replace the belt as operating it in an overtightened manner could result in internal damage to the timing belt which contains polyester cords similar to what is used in tire construction. If overtightened and run, these cords can break internally seriously compromising the integrity of the belt itself and there would be no discernable evidence of this by merely inspecting the belt.

Considering the extent of damage which occurs, and the cost involved correcting this damage, if the belt breaks while the engine is operating, I would not take the chance on a suspect belt, but rather would replace it, even if it was just installed...Jim '85TE



>> Edited by lotusguy on Wednesday 18th December 23:21

>> Edited by lotusguy on Wednesday 18th December 23:22