View Full Version : oil pump drive bush orientation?

04-25-2008, 08:39 PM
I'm on step one of the TR6 engine assembly, and already a question. :smile:

Is there a specific orientation for the oil pump drive bush? It has that flat slot across the top, and Bentley's illustration shows the small oil holes as being in line with that. But my oil holes are at a 45 degree angle to that.

Don't think it matters, but was about to drive it in and thought I'd check with everyone...


04-25-2008, 10:55 PM
I was about to put this on my list or vague instructions.
I put it right up there with the thrust washer install
pics in the Bently.

I'll be watching for the answers.

04-26-2008, 02:22 PM
Is this what you are talking about?

04-26-2008, 02:39 PM
Looks awfully "dry" in that hole. I would be very liberal with the engine assembly lube, especially on the bottom of the drive, with the gear tooth contact, on the sides of the bush, where they fit in the bore, and a dab on the top where the distributor drops in..

But's that just me....

I have seen first hand, lack of lube damage on initial startup.

I figure lube is like makin' love can never overdo it!

04-26-2008, 02:50 PM

That was just set in for test fit purposes when I came in with the camera. The new roll pin had just been installed and the studs were checked to make sure the threads were clean.

As they say here in RI, "Donja worry, we got a lotta grease for in dere".

The cam area is all lubed up with Comp Cam Lube, including the gear for this drive.

04-26-2008, 03:04 PM
Did you check to see if you needed to shim that pedestal, Paul?

04-26-2008, 03:50 PM
Yes, that's the bush... there's a pair of oil holes which presumably let oil from the main gallery in to lubricate the distributor drive shaft. I decided rotational orientation of the bushing itself, pressed into the block, didn't matter based on the geometry of those passages...

04-26-2008, 04:41 PM

I'm assuming that Erik checked that. I'll find out. He didn't mention it when we talked about the play in the old pin, so if he noticed that, I'm sure that he looked at ant required shimming.

04-27-2008, 10:38 AM
Is this what you are talking about?

Yeah, Paul, that's it. If I remember right, the Bently
says to have the slot oriented pointing toward the engine
block. Yeah, right, the slot goes all the way accross.
I suppose it doesn't matter which end of the slot, but they
don't tell you that.....and if it does matter, why, then
it's a 50/50 shot. Yep, right up there with the
thrust washer install pic in the Bently, too.

04-27-2008, 11:04 AM
2wrench, the slot is actually not running thru the center of the gear. I'm not sure how to tell you which way it should go, but it does make a difference.

04-27-2008, 11:34 AM
The slot changes as it is seated all the way and will be at a slight angle. I orientated my rotor as it should be and tipped my dizzy upside down to see how it was orientated. Noting the angle and offset I then installed the gear accordingly to mirror it and then be correct when the dizzy was installed.
I actually pulled the dizzy and moved it one tooth and tried it again untill I was satisfied. The fitting of the tach cable when the dizzy was set for the car to run was the defining critera for me.
Note that any picture in any book may be the reverse that is actually needed since the dizzy may have been apart and the shaft may have been reassembled so the blade may be 180 off.
Also be aware that the gear retainer needs to be shimmed to specification so the driven gear is not too tight or that it does not climb the drive gear on the cam and get some movement in the timing. Specs are in the Bently manual and it can be checked with a feeleer gage.

04-29-2008, 01:11 AM
I didn't quite follow the last couple posts there...

On the shaft bushing itself which drives into the block, I didn't see anything asymetric. I decided to orient the flats on the top of the bushing parallel to the block as shown in Bentley, even though the oil hole in the sides of the bushing were not in line with the slots, as portrayed in Bentley.

Is there a purpose for those slots in the top of the bushing? I couldn't determine one but would like to know if there is before I button the block up!

04-29-2008, 08:07 AM
The slot we are referring to is on the gear itself. The orientation will determine the position of the rotor in the dizzy.