FJ40 Thermostat Installation How To (9 Viewers)

Will Van

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By your description it should have worked just fine. Should not require Permatex in this application. Are you sure you had the bolts tight enough?

ps: use anti seize on those bolts.

Yessir, I'm fairly certain I had them snug enough.

Anyone know where I can find this thick rubber gasket? Neither SOR or CCOT has them.

6595-D651-9-FC0-4-E4-A-A85-E-32-D8-D45-C51-B3.jpg


Edit: It looks like FJParts.com has the thick rubber gaskets. I just ordered one and will report back. Thx.

Thanks, Roger.

Yes, the Parts catalogue shows 16341-60020 as the sandwich gasket between the two halves of the 2-bolt thermostat housing.
That factory gasket is 1mm thick and made of typical gasket fiber.

My question remains: why do some gasket sets include a 3mm thick rubber gasket for this use?
This rubber gasket is NOT 16341-60020 unless there has been a revision from the factory in the thickness and the material it uses for this purpose.

Whether using the above-referenced upper and lower 2-bolt housings, or their variations allowing oil coolers, BVSVs, etc., the gap between the two halves is usually too large to be fit with a single 16341-60020 fiber gasket when also using the rubber gasket above the factory 180*F thermostat. The fiber gasket DOES fit correctly without that rubber gasket above the thermostat, and perhaps this is used in hot-climate areas not needing a cabin heater, or anyone deciding to not run a thermostat (not advised).

This also remains true if substituting the factory 190*F thermostat as in the 8/80 and up 2F engine. (It appears the 190*F thermostat was introduced to help keep emissions in line during the "spaghetti years," where Toyota continued to struggle meeting stricter emissions standards in the US, Australia, and Europe.)

So................who is making this rubber sandwich gasket, what is its purpose, why is it included in some gasket sets, and does it have an official part number? Is it a cheap aftermarket substitution? Or should we all use the single fiber gasket and crank-down on those bolts to stop leakage? Is that part of the reason so many bolts shear-off when being removed? Anyone?
 
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Steamer

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Be sure the top half comes straight down when re-assembling. It's easy to bump the t-stat and knock it out of the recess without noticing. I have a couple of extra long bolts with the heads cut off to help guide it on without bumping it. I then hold it down by hand while swapping each bolt one at a time. Maybe overkill but I never had a leak there. I use the thin (2-hole) gasket with Sil-Glyde and Never-Sieze on the bolts.
I've found that the "gap" that the op speaks of, closes up as the fat round top gasket compresses.
 
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Just read all four pages twice . I'm having trouble getting my upper housing to seal. Is there two different OEM thermostats for fj40's that are different height? I don't even want to tell you guys how many times and gasket configurations I have tried in the last week ( ok eight) . And now I'm thinking the thermostat and rubber gasket on top of the thermostat may be keeping the upper housing from sealing to the lower. thank you for your help.

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Just read all four pages twice . I'm having trouble getting my upper housing to seal. Is there two different OEM thermostats for fj40's that are different height? I don't even want to tell you guys how many times and gasket configurations I have tried in the last week ( ok eight) . And now I'm thinking the thermostat and rubber gasket on top of the thermostat may be keeping the upper housing from sealing to the lower. thank you for your help.

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You might want to try your thermostat into the top housing with out the gasket and see if is fouling in the housing. I had that happen to me and the hole in the housing was hitting top of thermostat because it was slightly smaller than the edge of thermostat. I marked thermostat with a black marker pen, pushed it into housing and turned it around a few times. Then could see we're it was catching. I then machined the hole about 2mm bigger to give it clearance. After that the rubber casket fitted ok.
 
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You might want to try your thermostat into the top housing with out the gasket and see if is fouling in the housing. I had that happen to me and the hole in the housing was hitting top of thermostat because it was slightly smaller than the edge of thermostat. I marked thermostat with a black marker pen, pushed it into housing and turned it around a few times. Then could see we're it was catching. I then machined the hole about 2mm bigger to give it clearance. After that the rubber casket fitted ok.
I read that in your original post but it seems to me you should not have to do that if you have all of the right parts. I’m not saying what you did was wrong for you, I’m just saying I’m not a mechanic nor a machinist and want to make sure I have the right parts . I’m about ready to try a ten pound beater. 😁
 
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I read that in your original post but it seems to me you should not have to do that if you have all of the right parts. I’m not saying what you did was wrong for you, I’m just saying I’m not a mechanic nor a machinist and want to make sure I have the right parts . I’m about ready to try a ten pound beater. 😁
I am going to try marking it with a black marker. I think I will also try it without the thermostat.
 
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Just want to add, that when I compared the old and new thermostat, the new one was very slightly different shape on the upper side (as in vehicle), so I either the replacement Toyota gave was after market, or when it was made and the brass rolled it was over the tolerance. So also compare your old and new one and see if it slightly bigger and/or higher
 
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Just want to add, that when I compared the old and new thermostat, the new one was very slightly different shape on the upper side (as in vehicle), so I either the replacement Toyota gave was after market, or when it was made and the brass rolled it was over the tolerance. So also compare your old and new one and see if it slightly bigger and/or higher
The previous one was shorter. The current one is OEM and I assumed 😔 it would be fine . So now I'm trying to find out if there are fj40 OEM thermostats that are different heights.
 
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Does anyone know whether or not a thermostat for a 1968 to an 1980 fj40 is a different height than on from a 1981 - last model? They seem to call out a different one for those years.
 
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Does anyone know whether or not a thermostat for a 1968 to an 1980 fj40 is a different height than on from a 1981 - last model? They seem to call out a different one for those years.
Looking at our local online store in NZ All Fourx4 spares in Ozzie have two part numbers pre 1980 = 90916-03014 and 90916-03052 for all 2F engines after 1980 if that helps. Can send you the link if you want to see a picture of them?
 
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Looking at our local online store in NZ All Fourx4 spares in Ozzie have two part numbers pre 1980 = 90916-03014 and 90916-03052 for all 2F engines after 1980 if that helps. Can send you the link if you want to see a picture of them?
Yes please.
 
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Yes please.
If link dont work, copy and paste link into your browser
Pre-1980
 

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