a whirring sound

[Blazer Fan Dan]

I have an 85 245, and I'm hearing a whirring type sound, that seems to
be coming from the back. It's like the noise you hear when you're
downshifting, but it's not based on the clutch or gear-shift.

It seems to be worse when it's cold, and seems to be more based on the
speed of the vehicle, and not the rpms' of the motor. If I put in the
clutch, it doesn't make much (if any) difference.

I hope it's the power steering pump (which I'm replacing this
weekend). I'm thinking it might be the clutch cable, but i havent'
checked that yet. How do I check the fluid level for the tranny (if
you do?)?

 

[Gary Heston]

I have an 85 245, and I'm hearing a whirring type sound, that seems to
be coming from the back. It's like the noise you hear when you're
downshifting, but it's not based on the clutch or gear-shift.

It seems to be worse when it's cold, and seems to be more based on the
speed of the vehicle, and not the rpms' of the motor. If I put in the
clutch, it doesn't make much (if any) difference.

I hope it's the power steering pump (which I'm replacing this
weekend). I'm thinking it might be the clutch cable, but i havent'
checked that yet. How do I check the fluid level for the tranny (if
you do?)?

From the back would be the differential or main fuel pump. If you can
hear it when standing still, it's the fuel pump; only when moving,
the differential is probably low on fluid.

If you get a bottle of lube that has a pointed nozzle, you can push a
short piece of vinyl tubing onto it to make it easier to add; there's
more clearance across the car than in front of the diff. Holding the
bottle horizontal with the tubing stuck in the fill hole works well.

The power steering pump is in the front, and wouldn't make noise in
the back of the car.


Gary

 

[Blazer Fan Dan]

From the back would be the differential or main fuel pump. If you can
hear it when standing still, it's the fuel pump; only when moving,
the differential is probably low on fluid.

To be honest, I haven't noticed if it's when i stand still...but I
think it's only when I'm moving.

If you get a bottle of lube that has a pointed nozzle, you can push a
short piece of vinyl tubing onto it to make it easier to add; there's
more clearance across the car than in front of the diff. Holding the
bottle horizontal with the tubing stuck in the fill hole works well.

The power steering pump is in the front, and wouldn't make noise in
the back of the car.

Gary

thanks. I know this is a bit of a stupid question, but what lube do I
get? And where does it go? I'm going to change the oil (and PS pump)
this weekend, so I might as well do other stuff.

 

[Gary Heston]

thanks. I know this is a bit of a stupid question, but what lube do I
get?

IPD sells RedLine 75W-90 gear lube for differentials. I don't remember
offhand what I put in my 145, it's been a couple of years... Any name-
brand synthetic 75W-90 should work fine; someone with a owners' manual
may have a more precise answer for that.

And where does it go? I'm going to change the oil (and PS pump)
this weekend, so I might as well do other stuff.

The differential has two plugs on it, on the front of the housing. One
near the bottom is used for draining old fluid, which is probably
impractical in cold weather. The fill hole is above the drain. Both are
square, not hex, and will probably be a bit of a challenge to get out.
Apply penatrating oil, let it soak in while you're changing the oil,
and then try to get it loose. You may have to tap on the end of the
wrench with a hammer to encourage it a bit.

Once you get it out, fill to the bottom of the hole and reinstall the
plug. Sometime around August, you may want to drain and refill to get
most of the old lube out.


Gary

 

[Ross G]

May be the centre driveshaft hanger bearing. The comment about the
noise appearing when colder is a dead giveaway here. Try injecting some
lubricant under the rubber dust seal between the inner and outer races
of the bearing. If the noise stops, you have found the source. You may
be able to extend the life of the bearing by many year-s this way.
Certainly easier than removing the driveshaft and replacing the bearing.

 

[Blazer Fan Dan]

May be the centre driveshaft hanger bearing. The comment about the
noise appearing when colder is a dead giveaway here. Try injecting some
lubricant under the rubber dust seal between the inner and outer races
of the bearing. If the noise stops, you have found the source. You may
be able to extend the life of the bearing by many year-s this way.
Certainly easier than removing the driveshaft and replacing the bearing.

Thanks, I'll try that too. Even though the noise seems to have stopped
after I checked the rear diff.