18RG air con bracket (56k warning)

[GT1978]

This is for those that have been asking for some pics about how the Air con system is fitted to my 18RG.



As you can see, the main difference between the air con on a 18R(C) and an 18RG is that the compressor is mounted on the opposite side at the head.
Where the belt on the 18RC is tensioned by a separate adjustable pulley the 18RG compressor height is adjustable to tension the belt.

The belt runs from the crank across a double row water pump pulley, around the compressor pulley and back to the crank.


There are four brackets for the 18RG AC compressor. The main bracket that bolts to the head. The compressor is mounted to this with four bolts. The bolt holes in the main bracket are slotted to allow the compressor to be moved up and down.

(Compressor side of main bracket)


As you can see the AC main bracket uses the bolt hole for the engine lifting hook and so a hook is incorporated in the main bracket.

(Head side of main bracket. The four holes are used to bolt the bracket to the head)


The main bracket is attached to the head at the following points.

[GT1978]

There is a second bracket that is bolted to the base of the compressor. These two brackets are connected via a long bolt that is used to move the compressor to tension the drive belt.





This next Pic shows the compressor with the main and lower brackets in place.
The unlabelled arrows in this pic show the four slots used to bolt the compressor to the main bracket.


And this pic shows the compressor raised to the highest position using the adjusting bolt. I think I have seen this method used on some other Toyotas. Possibly with M series engines.
**Looks like I lost this pic at some stage**



As you may have noticed there are two other mounting points on the lower bracket. As indicated in the second last pic one side is bolted to a bracket that extends from the engine mount and the other bolts to a AC specific alternator bracket.
The standard alternator bracket has a straight slot where as since the AC requires the bracket to be in a fixed position the alt. slot is curved to allow the alternator to adjust. The end of the bracket also has a slotted hole for the AC. The hole is slotted vertically to allow the compressor to move up and down for adjustment.




At the rear of the compressor is the final bracket that extends from the engine mount and also has a vertical slotted hole for the lower bracket.

[airfireman1]

Nice write up, many people are always after info on the brackets, fortunately my RG has the rotary compressor bracket.
Cheers

[GT1978]

Some extra pics.

Close up of water pump pulley.


Top view of main bracket. In the middle you can see the hole for the adjusting bolt.

[Silly Rabbit]

Nice write up on it .......one word of warning on this though is have the bolts on the bracket to the head loctited on as with the air compressor weighing as much as it does they have a tendency to work loose from the rocking of the engine.......i used to have air-con on my 18RG and they stripped one of the bolt holes cos of the softer alloy head and the hard steel bolts.......also caused a crack at the front of the head near the timing chain as it is thinner alloy there and once again with the heavier weight and the rocking of the engine.........don't ask me how much friggin around it was to re-weld the soft alloy at the front.......in the end I binned the lot of it.........made the car 10kgs lighter and I just wind down the window

[GT1978]

I recently upgraded my alternator to a EA Falcon internally regulated job. To do this with the A/C setup you'll need to do one more mod than those described Here
This upgrade requires the alternator bracket to be able to pivot on the block mounting bolt to accomodate the different spacing of the alternator bolts. As you will have found out if you have A/C like that listed above the alternator bracket is fixed as it also supports the bottom of the A/C compressor.

To get around this I had to modify the alternator. Once the lower cast alternator bracket has been modified to take the new alternator I bolted the alternator in place and marked up the position of the slot in the top alternator bracket on the front of the alternator. I then removed the alternator and examined the marking on the alternator. Then I measured the point on the marking that was furthest from the edge of the casting and existing hole and drilled a small pilot hole through. I then increased the hole size until it was big enough to suit the tap I was to use. (think the original bolt size was M8 1.25). The alternator then mounted fine using the existing belt and leaving me approx 1" travel left for extra tensioning if required.

[The Witzl]

just an FYI - that is the EARLY type of 18R-G aircon compressor and bracket.

The later type mounts in the same position, but with a different bracket and has a smaller compressor. The bracket allows the compressor to be slid out to adjust tension on the belt - similar to a power steering pump or alternator.

I'll get some pics tonight of my compressor and bracket. Unfortunately i cant fit it to the engine, because it fouls on the extractors.

[The Witzl]

just adding to this thread.
Below are pics of the later of rotary type 18RGEU aircon compressor. As you can see its a LOT smaller, and waaaaaay more efficient than the massive piston type unit pictured above.

[egamirrorim]

I just found this thread.

Are the 18RG AC compressors different to the 18RC? I have a full 18RC setup that I was hoping to use on my RG, I had expected that I would just need brackets to be fabricated.