Rear Diff Union Part

[GB Junior Member Find all posts View Profile Close GB]

Just bought a union part from Dealer part No: T90404-51026 as image.



I want to use this to carry out the rear diff breather mod but now been told that the correct part should be 90404-51319 begin_of_the_skype_highlighting              90404-51319      end_of_the_skype_highlighting.

Can anyone advise which part is correct for use on Prado, Grande 4.0L auto 2008 model rear diff.

Also when using these unions do they simply screw into the diff or do you have to use some rubber washer to ensure a proper seal with the diff itself as when extending the rear breather up into engine bay it would be pointless if the actual union screwed into the diff does not provide a proper seal.

Any guidance appreciated.

PS
Can anyone advise how to minimise the photos as they seem very large when viewing the post and cutting off part of the original image.

[Chippy Addicted PP Member Find all posts View Profile Close Chippy]

Re: Rear Diff Union Part

PS
Can anyone advise how to minimise the photos as they seem very large when viewing the post and cutting off part of the original image.

Almost any image editing software will allow you to resize images.

The alternative is to use free image hosting ... like photobucket.com.
Photobucket allows you to impose an image size limit on your images.

Cheers
Chippy

[Schaffer Addicted PP Member Find all posts View Profile Close Schaffer]

Re: Rear Diff Union Part

When I did mine I looked at using a genuine union from a Camry (I believe) but in the end found that 1/4 Gas fitting (I think) fits and was cheaper and better IMO.

[clifton Advanced Member Find all posts View Profile Close clifton]

Re: Rear Diff Union Part

Also when using these unions do they simply screw into the diff or do you have to use some rubber washer to ensure a proper seal with the diff itself as when extending the rear breather up into engine bay it would be pointless if the actual union screwed into the diff does not provide a proper seal.

Any guidance appreciated.

PS
Can anyone advise how to minimise the photos as they seem very large when viewing the post and cutting off part of the original image.[/quote]

Hi GB,
Smear some "STAG" jointing compound lightly on the screw thread and srew into place until the hose tail union is tight, this will ensure a good seal. STAG is an old compound I have used for years. It now comes in a plastic tube from REPCO.

[Schaffer Addicted PP Member Find all posts View Profile Close Schaffer]

Re: Rear Diff Union Part

Another tip. Use a brush and then rag to clean away any loose crap before removing the original breather to minimise the poteintal for that same crap ending up inside your rear diff.

[Derb Senior Member Find all posts View Profile Close Derb]

Re: Rear Diff Union Part

Hi clifton. Gotta agree with the stag compound unless you wish to remove it sometime. This stuff is really seriously good shit! If you think you may ever need to remove it intact, thread sealing tape (Loctite TST) will do the job nicely - although make sure you wind it on in the correct direction with the tail trailing or it will just bunch up in a big mess. Cheers, Derb.

[GB Junior Member Find all posts View Profile Close GB]

Re: Rear Diff Union Part

Hi clifton. Gotta agree with the stag compound unless you wish to remove it sometime. This stuff is really seriously good sh!t! If you think you may ever need to remove it intact, thread sealing tape (Loctite TST) will do the job nicely - although make sure you wind it on in the correct direction with the tail trailing or it will just bunch up in a big mess. Cheers, Derb.

Thanks fo the advice.

I am thinking of getting some of this Stag paste. There is 2 options now Type A and Type B. I was looking to go for the Type B as this appears to be a thicker paste than type A. Also I though the Stag stuff did not set hard so cant understand there being a problem should you wish to remove the breather union in the future. Could anyone expand on why this might not be good if you want to remove it in the future.

Also the Toyota union that I have ( see my first post) does not look very robust. Would a similar brass fitting be adequate or would there be a heat or pressure issue.

[Schaffer Addicted PP Member Find all posts View Profile Close Schaffer]

Re: Rear Diff Union Part

Shouldn't be a pressure issue there GB unless you have totally stuffed it. The whole idea is to allow the inside pressure to be released through an elevated vent without allowing water ingress.

When I did mine I used a Pushing Brass fitting supplied from Metal Works along with suitable wound plumbing tape. When I purchased this I found out that this is what they use here in Adelaide on the CFS (Country Fire Service) vehicles for their breathers.

Very happy with the outcome, quite robust and very reseaonably priced.