water pump, threaded on block side

[PaulP38a]

In the quest to stop the whining noise in the engine bay, I repacked the idler wheels with grease and changed the water pump today. Had already established it was one of these... no noise when serpentine belt is removed. Not A/C compressor, but just maybe PAS Pump although I don't think so.

Purchased a new water pump from my favourite supplier (no prizes for guessing) and changed it over. 3x long bolts in ok, tightened up enough to stop the pump housing from moving, and then in with the 6x short bolts... didn't even get the 2 bottom bolts up to the recommended 17 lbf.ft torque when they started spinning. Bugger methinks! I've stripped the thread on the bolts, but no I hadn't. As the bolts came out so did bits of thread from the timing cover :o

The bolts appear to be approx 28mm long and approx 7mm dia on the shaft. NFI about thread pitch.

Am thinking I'll need to cut a new thread in the cover and use some slightly larger bolts... Anyone ever had to do this, and what size, pitch do you suggest please?

Cheers, Paul.

[33chinacars]

Well for one thing Paul being a Pommy car thread shouldn't be metric. If Ha Ha it was easy to get at use a hellcoil

[PaulP38a]

Yeah probably, they are metric heads though. I haven't upgraded to digital Verniers yet, and I'm about 20 years out of practise as a Mechanical Engineer and rely way too much on computers these days.

[daljames]

If you where in Sydney i'd recommend the "Threadman". He pulled out some exhaust manifold studs on my TD5 when i was replacing the turbo and exhaust manifold gaskets. Quality and too easy to deal with.

[Blknight.aus]

the pump on a rover v8 is easy enough to repair the threads on yourself...

ITs ally and if youve stripped the mounting holes for the smaller bolts you'll find that the tap that comes in the appropriate size helicoil/recoil kitwill cut the threads straight in without drilling BUT Its not the recommended practice. I suggest pulling the radiator out and using a right angle drill to get the supplied drill bit in to make tapping easy.

IF you've any doubt about doing it get someone like threadman to do it.

[justinc]

Metric heads (11mm or 7/16 spanner size) , imperial threads. 5/16NC I believe. Same block drillings/ threads as early 3.5. Its deceptive as they are rated in the metric 8.8 etc tensile system, not as the old bolts with the 3 or 6 radiating lines on the bolt head.

JC

[Rupert Prior]

the short bolts are metric 8x1.25mm. the long bolts are imperial 5/16unc.
it should be possible to just use longer bolts, but a standard 8mm helicoil would be better.

[justinc]

the short bolts are metric 8x1.25mm. the long bolts are imperial 5/16unc.
it should be possible to just use longer bolts, but a standard 8mm helicoil would be better.

Correct, they are into the timing case only.


JC

[andrew e]

Paul, i have a few spare timing cases here, i'll measure up and work out what length bolt you can get away with. IIRC the bolt only does up about half its available depth. It is 8mm metric corse and the larger ones which go all the way into the block (1/2" head) are the imperial ones 7/16. I guess that this was due to the origional design of the 3.5 buick block.

i really thought that there were 2 different lengths of 8mm bolts, but i have not changed one in a while.

If you want to change your timing case let me know i'll send you one.


Andy

[PaulP38a]

Must have been fate... I was driving back to work this arvo (in the Ute, not the Rangie) after a physio appointment and spotted a Lube Mobile van. Called the number on the back and asked about thread repairs. They said they couldn't help and advised me to look in the Yellow Pages.

A couple of minutes later I spotted another van with the sign "Capital Thread Repairs" and a mobile number. I called the number and got the driver... a bit wary at first, maybe he thought I was going to abuse him... Canberra drivers get that a lot :p

Explained to him what I wanted and he is going to come around to my place in the morning. :cool:

Tonight I undid all the good work that the physio did by removing the belt, idler wheel, water pump, fan and shroud to give the repair guy about 250mm clear access to the bottom two bolt holes.

The shroud was the hardest thing to remove... must have been a few years worth of mud and dirt holding the bottom of it in place.

Will update the situation sometime tomorrow.

I guess it wil probably cost a small fortune to fix, if he can. Not what I really want to spend given that I intend to sell the "Blue Thunder" Hard Rangie once I transfer the cool bits over to the new one.

Cheers, Paul.

[Blknight.aus]

if his going rate is the same as my guys going rate and with that much access it should cost you less than $70.

My guy waives the call out fee If I can wait till he's in location for something else.

[PaulP38a]

if his going rate is the same as my guys going rate and with that much access it should cost you less than $70.

Close, he charged me $80 for doing the two holes and it took less than an hour.

New helicoil threads look good and work well.
http://paulp38a.com/gallery/d/4830-1/IMG_2837.JPG


close up of one of the new threads
http://paulp38a.com/gallery/d/4833-1/IMG_2838.JPG

Off to get a new gasket tomorrow as I no longer trust the other one as it has been pulled out twice.

Cheers, Paul.

[glenhendry]

Great news! Cant complain too much about a $80 job when its a mobile professional.

Glad it working out - good luck with the remainder of the job.