View Full Version : TR2/3/3A tr3 head rear oil leak

12-16-2008, 12:56 PM
Hey guys,

I don't have a picture, but while working on the car last night I noticed that there is a an oil leak from the back end of my head. There is a bolt screwed into the rear upper driver's side face of the head, directly facing the firewall. It seems impossible to get a wrench in there. Also, I don't see this bolt in any of the engine diagrams I have.

Is this stock? Thoughts on how to plug it?


12-16-2008, 01:08 PM
I have a bolt there with a lock washer underneath it and luckily no leak. It's a 9/16ths and I got a snap on jointed drive on it.
Looking at the exploded motor/head diagram I don't see it though. An oil gallery plug?

12-16-2008, 01:35 PM
Looking at the exploded motor/head diagram I don't see it though. An oil gallery plug?

It must be, given how much oil is flowing from there!

What kind of washer should I use? Normal lock washer? Copper?

12-16-2008, 01:58 PM
Mine appears to be a normal lock washer. I'd clean the threads in the head well and the bolt and add a dab of sealant to the bolt threads near the bolt head before tightening then let her sit awhile to cure.

12-16-2008, 02:22 PM
There is an oil gallery plug on the LH rear corner of the head, for the drilling that carries oil from where it comes up from the rear cam bearing, over to the passage up to the rear rocker pedestal. Should be a copper washer under the head.

But it shouldn't be that hard to get to, ISTR I just stuck an ordinary offset box-end wrench on mine. If you install the aftermarket external oil feed, that bolt gets replaced with a banjo fitting.

Sorry, don't have an illustration handy.

02-12-2009, 04:13 PM
I'm ordering some parts from TRF and having a hard time locating this rear oil gallery bolt & washer in the original parts catalog (possibly because the edition I have doesn't cover 3A's). Can anyone supply me with the numbers?


02-12-2009, 05:28 PM
Bolt is HU0953 (which is just an ordinary 3/8NC by 3/8 bolt), washer is 500464.

Not illustrated, but should be listed in all SPCs, as it's found in all TR2-4A motors.

02-12-2009, 05:37 PM
Aloha Gavin,

I had at one time installed the external oil line from the oil gallery to the rear of the cylinder head, but later removed it. ISTR the plug on the cylinder is the same as the those plugs along the oil gallery running along the driver's side of the engine block. I used a copper sealing washer under the plugs. Perhap Randall can confirm this.

I couldn't find one in the TRF data base but MOSS has them, part # 328-300 for the plug and 324-720 for the washer. A new copper washer is probably available at most FLAPS or hardware store.

02-12-2009, 06:14 PM
328-300 is listed for the oil gallery plugs on the side (not the cam bearing retaining bolts), but the Moss US website shows them as NLA.

My recollection is that there is something special about those plugs, making them different than the one of the back of the head (which is an ordinary standard bolt), but I do not recall what offhand (and might well be mistaken). But ST thought there was a difference, as they assigned different part numbers.

BTW Horrible Freight sells a kit of copper washers (https://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93324) that comes in very handy. However, ISTR the plug on the back of the head has a ridge around it such that the OD of the washer is also important. An ordinary hardware store washer (like the ones from HF) might not fit.

Apparently, the problem with the rear screw is that it's too short. MMC has them listed in that length only in stainless. But it shouldn't be too hard to pick up a longer bolt and cut or grind it down. MMC has them listed in 1/2".

02-12-2009, 06:15 PM
Perfect guys- now I see it in the catalog. Thank you. Of course it's labeled as a "screw"- I would have never figured that out!