Well we have quite a bit of snow here in the Seattle area and I put the '85
K5 Blazer into 4WD of which it hasn't been in for a few months at least
unless pulling out my 9000 lb boat out of the water. Anyhow, when driving
straight and getting over 25-30 mph, I get quite a thump in the front end
somewhere about every so often. The 4WD is engaged because I can feel it so
I know that isn't the issue. I have Warn manual hubs and then shift on the
floor (which is factory). I haven't done any service recently to the front
axle so not sure what is going on there. Anyone have any clues as to what
this might be? Didn't notice this thump when turning, just when going
straight and over 25-30mph. Thanks.
Mark, sorry for the delay, but life was calling =)
If just the spider gears were involved and there is no ring or pinion damage
it can indeed be a cheap fix.
My cost was about 40 bucks total.
30 dollars for a used spider set at the local u-pull-it
and 10 dollars for incidentals. Gear oil, blue goop, and band-aids.
Be sure to wipe the case dry to get all of the broken pieces out.
Look around in there carefully, make sure there is no debris left in
the case or you may be doing it again.
I'm almost betting that you inadvertently let the case go dry, or nearly so.
If you have never done anything like this before, offer a knowledgeable
friend a six-pack to give you advice while you are doing the work.
A first timer should be able to do it in a few hours, start to finish.
Sounds like it's time to give me your truck so I can combine you 85'
K5 and mine into 1 better ride..... gimme a call if you decide you
want to give me your truck... :0)
I think it's the spiders... sounds like it's time for a nice locker...
And no, front end work 'taint cheap... nutin' be....
-The Lonely Grease Monkey
1985' K5 305CUI TH700R4 NP208
"Ignorance is preferable to error; and he is less remote
from the truth who believes nothing, then he who believes
what is a wrong."
- Thomas Jefferson
Well I did find out where the problem is coming from. It is coming from the
hubs and not the axle like first thought.. I found this out because I
unlocked the hubs and then shifted into 4WD and the thumping was no longer
there. Maybe the hubs are just dirty or have ice in them or something. It
has been pretty cold here. What you all think of that? Thanks.
BTW, Lonely Monkey, my truck rocks, just occasional irritations. Heck, it
can pull 9000 lbs and idle up the muddiest hill better than a jeep. Does
great in the snow too. Do want new tires though.
Mark, you may or may not have found the problem.
If you unlocked the hubs and shifted into 4x4 the spiders
weren't doing anything.
Try locking the hubs and drive in 2x4. See if the thumping comes back.
Please let us know what you find.
It doesn't do it when in 2X4. Just when in 4X4. The last trick I tried upon
a suggestion from a mechanic I go to sometimes. He said he is willing to bet
it is something to do with the hubs. Maybe dirty or dry hubs/ What are your
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