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How many thermostat flange widths exist for VN V6 S1???

48-215

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Hello folks, I have a VN S1 V6 motor, thermostat is at rear, in a 4wd. I just tried to change the thermostat, got it all apart eventually, put it back together with a Dayco DT22A (its an 82C thermostat, but the 22B is still 44mm) thermostat, the flange is full width if the housing 44mm. I also used a new Dayco O ring too. Thing is the alloy thermostat housing has a recess machined in it, to take the thermostat I assume, its maybe 40mm (39.??) .
The thing leaked once the stat opened up. When I bolt the housing down with tstat in, the housing will not sit flush on the inlet manifold on the opposite side to the bolt. The gap is probably pretty close to the thickness of the thermostat flange but the single bolt on one side pulls that side down, and the other up.

Am I using the wrong thermostat despite it being the part listed for it? I cant find a part number with a 40ish mm flange. The housing seems OK... manifold seemed fine where the housing drops in too. The leak is noticeable... I could see coolant coming from under the housing and pretty much all the way around beteeen housing and inlet manifold. I thought it was the hose at first then I saw it flowing from under the housing??

Cheers, Gary
 
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Welcome to the forum.
Right name, right location, but it's bin too long since I did a thermostat on a VN, however, if you try the Superthief link you may find a stat to suit.

Other than that, a trip to Bursons may get you the correct one, or Repco ?? but I recommend Bursons at Sugar Rd, and take the stat housing with you.
Also give the stat housing a good going over to clean it with alloy cleaner and/or wire brush and a good sight check for cracks because they have been known to crack then close up although I believe by you post you have a gasket/not fitting flush problem.
Stats are usually the easiest of things to get right provided you fit the stat into the housing for a test fit and you mentioned an o ring so maybe it needs a gasket
and also place the stat in a saucepan of water and bring it to the boil to test it is operating correctly before final fit.
Another problem is using gasket goo on an o ring can cause the ring to squish out so best clean everything better than you teeth then fitted dry.
 

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What diameter was the thermostat that came out?
 

48-215

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Problem solvered.

Took about half the recess depth off the housing with a file (maybe a bit more off one side than the other :D ), and the housing now pulls up square and the oring seals perfectly. I think some coolant is getting past the thermostat though (took a tad too much off maybe) as the VDO mechanical gauge which is spot on at 100 C (fan switch is triggered at 100), reads 70ish C on the highway.

Welcome to the forum.
Right name, right location, but it's bin too long since I did a thermostat on a VN, however, if you try the Superthief link you may find a stat to suit.

Other than that, a trip to Bursons may get you the correct one, or Repco ?? but I recommend Bursons at Sugar Rd, and take the stat housing with you.
Also give the stat housing a good going over to clean it with alloy cleaner and/or wire brush and a good sight check for cracks because they have been known to crack then close up although I believe by you post you have a gasket/not fitting flush problem.
Stats are usually the easiest of things to get right provided you fit the stat into the housing for a test fit and you mentioned an o ring so maybe it needs a gasket
and also place the stat in a saucepan of water and bring it to the boil to test it is operating correctly before final fit.
Another problem is using gasket goo on an o ring can cause the ring to squish out so best clean everything better than you teeth then fitted dry.
Cheers for the welcome mate...
Ive done plenty of thermostats, just never one like a Series 1 VN V6. See image attached. It was obvious to me the stat was too wide but its all thats listed for them. I hoped there might be someone here that might have remembered the right part number.

Series 2 is different .

Housing was cleaned thoroughly with an old dulled scotchbrite pad on a die grinder and wire brush. The oring is the only seal they have, part of the housing with the oring pushes down inside the manifold with a single bolt to retain it. These things were rushed in from Buick and converted from front wheel drives when the RB25 deal with Nissan fell through so the early ones had some quirks that took time to iron out. The problem is purely the flange width on the tstat, and a single bolt to pull the housing down. If it had two bolts or the right flange on the statm,it would seal fine. Just have to mod the housing to make up for it but last night I was still hoping to find the right tstat which Im betting is no longer available.

They all list the 44mm flanged thermostats no matter what year VN. tried Ripco, Supercreep and Holden

Dont get me started on Repco, Rang Holden, they cant find their feet without a VIN.

The attached image is the housing and oring. The second pic, red arrow is the ledge or the little recess for the right stat. The listed stats all sit flush with outer edge of that part of the housing. Thats what I filed down to get it to sit right with the wrong 'listed' tstat..

The Tridon screen grab is for 1988 and it shows 44mm, but that ledge in the housing is just under 40mm and its not there for nothing. The housing outer edge is 44mm but with one bolt it will never pull down square and flush.


What diameter was the thermostat that came out?
If only it was that easy... it was sans tstat.

Cheers.
 

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Last time I did this was probably 15 years ago.
 

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Mine didn't leak but then I'm guessing I had the correct thermostat. Took a bit of effort to free the thermostat housing though if I remember correctly and possibly the bolt pulled it slightly to one side (as it would having only one bolt). I seem to remember spending a bit of time cleaning it all up.
 
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48-215

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If you have the wrong tstat, it wont seal without mods. If you imagine a line from the bolt to the opposite side as 6 and 12 oclock, the only parts of the oring sealing are 3 and 9, 6 and 12 dont touch the face inside the manifold. The leak had a good flow I could watch it cascade down over the bellhousing and the source was from all around the housing at the manifold. The housing sits too high all around by the thickness of the stat flange, the bolt pulls down from beyond the edge of the stat lip so it can only cause it to sit at an angle as the bolt end gets flush with the manifold, it angles the opposite side up. Its meant to sit flush all round. It now does sit perfectly flush and seals.

Yeah getting it out wasnt pleasant. Soft hammer knock it toward the left, then insert a fat punch in the open end to pull it back the other way cant get hammer in for that side, back and forth, and being a 4WD I had to walk around the car for each direction, then once loosish I used a pry bar to pop it upward working back and forth from two ends to lift it square.
 
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