Transmission Jack Adapter
I have found even the dedicated tranny jacks that are available for rent are
also too tall to clear the do-it-myself height of jackstands. Enough height
to clear the car for any of these commmercial jacks is too high for me. I
don't feel comfortable working under the car at those heights with the small
footprint given by the smaller jackstands. The commercial tranny jacks seem
to assume a lift of some kind will be used.
I've built a tranny pad for my floorjack. Real simple. Start with about a
18" square piece of 1/2" thick wood. I cut mine to be just over the size of
a TH400 pan leaving enough extra to put another strip of wood the same
thickness at the front and rear of the pad.
The top of the wood cradle showing the recessed bolt head/washer
and front/rear wood strips to give some stability and prevent movement.
This keeps the tranny from
moving front to rear. I then use anything from a couple pieces of chain with
a bolt or a belt to hold the tranny in place laterally. You could add side
pieces of wood as well but the chain/belt is most secure and allows more
movement as you get close to slipping the tranny in place. If you have need
for other size pans, the epxenditure for another piece of wood will never
get anywhere near the price of a tranny jack you can't use anyway.
The bottom showing the marks left in the wood from the
jack pad. As you can tell, this thing has had some use!
I mounted the board to the floorjack pad with two 5/16" coarse thread bolts
and recessed the wood so the bolt heads and washers (for support - the wood
is pretty thin) are below the flat part the tranny rests on. If you drill
and thread a couple of holes in the floorjack pad you can mount the tranny
holder tightly to it without the mounting bolts interfering with a full drop
of the jack pad into the jack chassis. This is the min. height possible with
this idea. Obviously where you drill and tap the holes in the jack pad will
dictate the location of the holes in the wood. As you get the tranny close
you may need to loosen the chain/belt a bit for alignment with the block
dowel pins but it's pretty easy.
The floor jack pad. You can see two holes about 11 O'clock
and 5 O'clock. I drilled and tapped them for the bolts. I first just drilled
holes and ran bolts through. Unfortunately the bolt/nut would interfere with
full frop of the jack in certain positions. Tapping the hole and using the
right length bolt works better.
Works for me and costs next to zip to build. Not as fancy as the fully
adjustable types but it is, in my experience, stable. I've put quite a few
TH400's (dozens I guess over many years) in and out of my cars with this
setup and have never dropped one or felt the height of the car was
dangerous. I've used the same board for years. The height is low enough that
the most I have to do to get the tranny from under or back under the car is
tilt the high part of the case a bit (raise the tailshaft).
All my serious auto tranny work is with TH-400's so I built the pad to match
the length of that pan. As I said in my post, you could put on side pieces
as well and in that way prevent trans movement in all four directions. I
left them off because it leaves me more room to jockey the trans around when
trying to get it to seat on the block. The jack doesn't move well as you
know.
These pics also don't show a strap or chains which need to go over the
trans, but I strongly recommend and use them. With retainers on all four
sides and chain/strap to hold it there, this thing shouldn't go anywhere you
don't want it to.
Remember, this isn't the most stable situation in the first place. PLEASE BE
CAREFUL! But it sure beats trying to lift the d**n things with muscle power.
The ideal way is a lift and dedicated adjustable transmission jack. But this
works for me and most important, the price is right.
If you want more info, just ask. AND BE CAREFUL, these things weigh a ton.
I've never had a problem but I can't know everything about your situation. I
think at a minimum you have to have a good, hard, flat solid floor. Doing
this in the dirt is a definite no-no. IT WILL TIP OVER!
I am sure that some folks could provide improvements to this
idea and I'd love to hear them.
Bob Handren
OCA 7728
67 W-30 MODIFIED
70 SX convert
70 Vista Cruiser (under contruction)
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