Re: [DMCForum] Help me change my TABs on my Auto DeLorean........please

["Walter Coe" <Whalt@xxxx>]

> Has anyone got any advice on how to change my TABs on my automatic
> DeLorean.

James, sorry this is long as usual, but there are many important things to
mention.

Replacing TABs with an automatic transmission in the way requires a few
extra steps. You are also more limited with the size/shape of the wrenches
that will fit.

Initially support the car using jack stands or a lift that allows the wheels
to hang. Then use a floor jack under the rear wheel as necessary to shift
the load on the TAB so that you can maneuver the trailing arm to free the
bolt. You will need to use the same technique later to put it back
together.

Getting the bent bolts out:
A straight bolt will slide in toward the transmission and come out. On the
drivers side (LH) w/auto tranny, the bolt will be too long to clear without
removing the trailing arm from the rear hub carrier. If either bolt is too
bent to slide out of the bushing, it will be necessary to cut it out. An
electric reciprocating saw (Saws-All) works great.

You have two choices involved with removing the trailing arm:

1) Disconnect the brake line. Fluid will drain out. You need to find a
fitting to plug the line or the fluid will continue to drain until the
master cylinder is empty. Remember that DOT 4 brake fluid works well as
paint remover. It will discolor the epoxy and if left on for long will
bubble & loosen it. My favorite tool to plug the line is a sharpened golf
ball "T". Give it a nice long tapered point and have it ready before you
open the line. An alternative is to use a vacuum line cap such as is used
on the door's courtesy light switches to extend them. Be careful not to use
anything that will break off in the line or leave contamination.

-or-
2) (Not what I recommend) You leave the brake system sealed. Instead you
unsnap the hard line from the clip holding it to the trailing arm. Take the
caliper loose and bend the hard brake line while you disconnect the trailing
arm from the rear hub carrier. With the trailing arm free, pull the forward
end of the trailing arm off the TAB while pushing the TAB out.

Issues with the TAB bushing:
If your TABs were bent, most likely your TAB bushings are damaged and will
need to be replaced. It isn't uncommon to have the bushing's inner sleeve
jamb on the bolt and come out with it. The snub washers may also be worn.
The vendors don't normally sell these with their TAB kits. Usually you can
just flip the washers over putting the worn face to the other side where it
doesn't matter. Most people orient the new TABs the same way as the factory
installed them, i.e. heads facing the transmission, threaded ends facing the
wheels.

The bushing is held to the frame with two bolts. These bolts should have
jamb nuts; however, with automatic transmissions, the forward jamb nut is
generally left out because it is extremely difficult to reach unless you
remove the transmission. It is easiest to reach these with a small crescent
wrench or a ratcheting box-end wrench. If you can't reach it to loosen it,
consider letting it break off as you back the bolt out. Once the bushing is
out, you will have more room to remove what is left.

Putting it back together:
Prepare the TAB bushings by applying a thin light coat of silicone grease to
both faces. Prepare the TAB by applying a thin light coat of anti-seize
grease. Be careful to have the threaded portion of the bolt free of any
lubrication because the torque specifications for it are "dry".

Issues with wheel alignment shims:
People sometimes make the mistake of using the wrong kind of shims. Some
varieties are too soft. They will crush and fall out. Some people use
non-OEM shims either because they don't have the right kind on hand or they
want something thinner for fine wheel alignment adjustments. If your
replacement shims are of questionable hardness, sandwich them between two
OEM shims. Where the hardness really matters is where the shims touch the
sleeve in TAB bushing and the sleeve in the trailing arm. The inner shims
have a wider load distribution where hardness isn't as critical.

Generally most cars left the factory with 3 shims on the drivers side and 4
on the passenger side. If you don't know how many shims per side your car
had before you started, this is a good rule-of-thumb to go by if you are
going to drive the car before you realign the rear wheels.

When torquing the TABs to spec, it is best to hold the head of the bolt
stationary and tighten the nut with a torque wrench. If you tighten from
the other side, you will also be measuring the friction of everything
rubbing on the bolt . It is a challenge to find a wrench that will fit the
head of the TAB while in the frame. I have found that flat ratcheting
box-end wrenches fits great, holds itself in place but is hard to get out
when you are done. A better choice is an offset box-end wrench if you have
one that fits. There is not enough room to fit a socket & torque wrench
over the TAB's nut while the body is on the frame. My favorite trick is to
use a crow-foot adapter on the end of a torque wrench. Even better is a
line wrench crow-foot because it grips more sides of the nut. Depending on
the manufacture, some combinations work well together; others won't fit. To
keep the torque wrench setting accurate with the offset of the crow-foot
adapter, take the final torque reading with the crow-foot adapter at a right
angle to the torque wrench.

The vendors' consensus on the optimum torque for the OEM TAB is 60 ft-lbs
for the first nut and 55 ft-lbs for the jamb nut. You should have the
weight of the car supported by the rear wheels when you tighten the final
torque because otherwise you pre-load the bushing. My choice to do this
without an elaborate lift is to lower the rear wheels onto ramps leaving me
plenty of room to still fit under the car.

If you are having trouble with the TAB shield studs spinning in the
fiberglass, I highly recommend the kits offered by John Hervey or PJ Grady.
They are worth every penny.

Let me know how it turns out. If you can suggest any changes or
improvements to the above instructions, please let me know. If you take
photos while you work, we can use them to help photo-illustrate this
procedure.

Walt