[TR] Lessons learned: A-type OD and gearbox assembly tips

J.C. Hassall jhassall at blacksburg.net
Sat Oct 13 17:36:50 MDT 2007


I just about lost my religion yesterday trying to reassemble the A-type 
OD to my TR4 gearbox, so thought I'd post some lessons learned; 
hopefully they'll benefit someone else.

Ensuring that the splines align perfectly so the mainshaft will slide in 
easily is fiddly.  Lightly lever the two bridge bars forward and spin 
the drive flange until the splines align perfectly.  Tap the bridge 
pieces rearward and align the splines perfectly with the pump axis, then 
align the mainshaft splines vertically (so the splines will mesh). 
Ensure that the pump cam lobe is at the 12 o'clock position.  Don't 
touch the drive flange.

Tie the pump roller in the full down position.  I looped bare 28AWG wire 
behind the roller, then wrapped it tightly to one of the solenoid side 
cover studs.

For the moment, use flat washers instead of lock washers on the long 
studs.  Lightly grease the mainshaft splines, slide the OD onto the 
mainshaft and tighten the nuts until there is about a 1" gap between the 
units.  Use a screwdriver to lever one of the springs to the rear, which 
will lock the sun gear so the splines rotate together.  You can then 
rotate the drive flange to mesh the splines on the mainshaft.  Be sure 
that all springs are properly seated on the adapter plate.  Continue 
tightening the nuts.  If you encounter significant resistance with a gap 
of about 0.44 - 0.47, the OD splines aren't properly aligned, so de-mate 
the units and start over.  Once you're past the 0.44 (+/-) gap, continue 
tightening.  At a gap of about 1/4" the pump should be under the cam. 
If you're as A.R. as I am, remove the pump filter and the 5/8" bolt to 
gain access to the pump.  Release the pump roller and rotate the drive 
flange a full revolution.  The pump should move.  If not, de-mate the 
unit, check to ensure that the pump isn't bent and moves easily, and 
start over.

When properly assembled the drive flange should easily turn the 
mainshaft (gearbox in neutral).

It wouldn't hurt to pack some grease under the pump to prime it.

Hopefully these tips will help someone.

Jim

-- 
J.C. Hassall
Blacksburg  VA
64 TR4 in autox preparation
95% finished, 90% to go


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