Big - Rear End Project has begun!
#21
I did not take out the Fulcrum Pins, it was obvious that they were going to be very difficult to remove, with no perceived benefit. Other than one lower bushing in the passenger side shock which gave that dull thud there was nothing operational wrong with the rear end. The lower arms went into full droop when the axle was turned just the right way, made it easier to paint and clean in some areas.
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plums (03-16-2016)
#22
Thanks for letting me know.
It's become kind of a "thing" with me to figure out how much
the lower arms should move when new.
The ones on my reserve unit will flex due to the rubber, but
the pins are seized to the arm and inner bushing sleeve. All
the movement is in the twist of the rubber.
It's become kind of a "thing" with me to figure out how much
the lower arms should move when new.
The ones on my reserve unit will flex due to the rubber, but
the pins are seized to the arm and inner bushing sleeve. All
the movement is in the twist of the rubber.
#24
How were you able to remove the pins?
Been soaking mine in storage with ATF for over six months
now.
#25
One came out easily but one was seized solid in the bush and wishbone sleeves. I cycled through heating the bolt a bit, spraying in Plusgas, shocking the bolt end with a hammer and chisel and using an impact on the bolt head. Took a couple of hours including soak time, tea breaks etc.
I seem to recall heating the bolt helps draw in the releasing oil as it cools. Most of the corrosion was on the bolt itself where it passes through the wishbone sleeve next to the rear bushing.
I seem to recall heating the bolt helps draw in the releasing oil as it cools. Most of the corrosion was on the bolt itself where it passes through the wishbone sleeve next to the rear bushing.
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plums (03-17-2016)
#26
No tea and no heat in the rented storage locker.
At least not hot tea.
The rust between the bolt and the wishbone itself is what
has always confused me. It does not exist at the factory.
So maybe that is accounted for by the bolt crushing against
the inner sleeve to form a solid unit of wishbone + inner sleeve
making the question of the wishbone being seized to the bolt
later in life immaterial.
But in earlier versions, the fulcrum pin ran in bearings. Quite
a big change in expected behaviour.
At least not hot tea.
The rust between the bolt and the wishbone itself is what
has always confused me. It does not exist at the factory.
So maybe that is accounted for by the bolt crushing against
the inner sleeve to form a solid unit of wishbone + inner sleeve
making the question of the wishbone being seized to the bolt
later in life immaterial.
But in earlier versions, the fulcrum pin ran in bearings. Quite
a big change in expected behaviour.
#27
On my setup the wishbone is sleeved with what looks like some sort of brass/alloy inserts - no bearings. There's no corrosion on the inserts as far as I can see (no surprise if it's an alloy) it's the bolt that has corroded. My guess is once it's torqued up the whole setup will be locked up which is why the corrosion can set in. On the other hand, why sleeve the fulcrum bolt if it's never going to rotate? I'm at the cleaning and painting stage so hopefully all will be clearer in the next week or so.
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plums (03-17-2016)
#28
#29
OK - finally started to put it all back together. In response to Plums question about the range of movement of the lower fulcrum, the answer is that the assembly locks up once the nut is torqued up. In other words, the fulcrum movement is limited by the elasticity of the rubber in the bush - there is no rotation around the fulcrum bolt. I've torqued to 100 Nm as per table from the manual to test this. I will back it off and retorque the nut once the subframe is back on the car and the wheels at normal ride height.
Just out of curiosity, I have never read the definitive reason why torque specs are often given as a range. Does anyone have the answer?
Just out of curiosity, I have never read the definitive reason why torque specs are often given as a range. Does anyone have the answer?
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RaceDiagnostics (04-04-2016)
#31
So the inner sleeves of the rubber bushes are being
locked into the bronze sleeves of the lower arm when
tightened?
I have heard only one mention of why there are two
numbers in torque specs. The explanation was that
one was for a new fastener and one was for a reused
fastener. The person who would know is JF member
Thermo as he is certified in the area.
On the other hand, there is a general rule that a
lubricated fastener should be tightened less than
a dry fastener. The rule of thumb is 25 percent.
The table shows differences between high and low
of 20 to 25 percent. Except for the very critical
hub nut.
Right or wrong, I generally go for a lubrication and
the high end of the published numbers. Always feeling
for unexpected elasticity along the way. Sometimes I
go for the middle but never the lower number.
On questionable applications where the published numbers
are all over the place, I also consult fastener manufacturer
tables. One example is differential ring gear bolts. For a
given application, you can find all sorts of numbers quoted
in the internet gospel. Most of them are too low and there
are many stories of differentials grenading due to bolts
backing off and roaming around the gear teeth. It's not
just the torque, it is also sometimes people using the
wrong fastener. For example, a non-flanged bolt when
the original was flanged, or the wrong radius under the
head.
locked into the bronze sleeves of the lower arm when
tightened?
I have heard only one mention of why there are two
numbers in torque specs. The explanation was that
one was for a new fastener and one was for a reused
fastener. The person who would know is JF member
Thermo as he is certified in the area.
On the other hand, there is a general rule that a
lubricated fastener should be tightened less than
a dry fastener. The rule of thumb is 25 percent.
The table shows differences between high and low
of 20 to 25 percent. Except for the very critical
hub nut.
Right or wrong, I generally go for a lubrication and
the high end of the published numbers. Always feeling
for unexpected elasticity along the way. Sometimes I
go for the middle but never the lower number.
On questionable applications where the published numbers
are all over the place, I also consult fastener manufacturer
tables. One example is differential ring gear bolts. For a
given application, you can find all sorts of numbers quoted
in the internet gospel. Most of them are too low and there
are many stories of differentials grenading due to bolts
backing off and roaming around the gear teeth. It's not
just the torque, it is also sometimes people using the
wrong fastener. For example, a non-flanged bolt when
the original was flanged, or the wrong radius under the
head.
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michaelh (04-02-2016)
#33
Front end is good, so no major plans there. Next winter my project will new front seat leathers and hopefully I can find a new interior carpet. That should eat up my $1000 a year upkeep budget.
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