Transfer Case Oil Pump Retainer/Wear Protector
09-04-2009, 12:32 AM
#11
Hold the horses here. . .the metal clips have 2 problems; 1) the early-early clips were dead soft steel and it was common to see them cut in half. Later clips were harder and more recently GM came out with the new design shown above. 2) All metal clips or inserts WILL wear the soft magnesium. This includes other aftermarket parts with 5 metal edges that contact the magnesium (also watch out because this other part pushes the pump forward by the thickness of the plate).
I have been very involved with this issue. One of the biggest questions I had was why does the magnesium have such terrible wear properties? Bottom line is the AZ91D alloy is too soft. Wear is seen at the pump tab contacts, clip, bearing pockets, shift fork rails in this transfer case (and Ford magnesium T-cases too).
I sent out sections of both aluminum and magnesium transfer cases and had them hardness tested at room temp and at operating temp. The magnesium gets alarmingly soft when hot and that is why they wear wherever (moving) metal contacts it. This link is the summary of these tests --> http://www.sonnax.com/tech-articles/TASC-TIP-11-07.pdf
The revised GM clip, the aftermarket 5 tab metal clip and any other metal in contact with the magnesium WILL wear the magnesium. With these facts in mind, we developed the Sonnax Pump Plate 100246-02K, see information link here --> http://www.sonnax.com/announcements/100246-02K.pdf
The eliminates metal contact between the pump and the magnesium case. Instead of metal contact we use high density plastic (like snowmobile hyfax slides). This material has proven itself in testing and in service. With this part you can expect a 100% fix and ZERO wear of the magnesium housing in the future that is so common on these.
Pulling your T-Case apart when you have it out is a great idea and not too difficult to back together.
Gregg
I have been very involved with this issue. One of the biggest questions I had was why does the magnesium have such terrible wear properties? Bottom line is the AZ91D alloy is too soft. Wear is seen at the pump tab contacts, clip, bearing pockets, shift fork rails in this transfer case (and Ford magnesium T-cases too).
I sent out sections of both aluminum and magnesium transfer cases and had them hardness tested at room temp and at operating temp. The magnesium gets alarmingly soft when hot and that is why they wear wherever (moving) metal contacts it. This link is the summary of these tests --> http://www.sonnax.com/tech-articles/TASC-TIP-11-07.pdf
The revised GM clip, the aftermarket 5 tab metal clip and any other metal in contact with the magnesium WILL wear the magnesium. With these facts in mind, we developed the Sonnax Pump Plate 100246-02K, see information link here --> http://www.sonnax.com/announcements/100246-02K.pdf
The eliminates metal contact between the pump and the magnesium case. Instead of metal contact we use high density plastic (like snowmobile hyfax slides). This material has proven itself in testing and in service. With this part you can expect a 100% fix and ZERO wear of the magnesium housing in the future that is so common on these.
Pulling your T-Case apart when you have it out is a great idea and not too difficult to back together.
Gregg
Originally Posted by kbracing96
When I did my 80e swap, my clip was not broken nor was the case warn, but I put the new style clip (per KySliverado's thread ) and all is good to go . Oh, and my truck was around the 90k mile mark when I did this.
09-04-2009, 07:50 AM
#12
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It’s reasonably priced. . not too much more than an OEM rear seal for the transfer case. I looked for on-line retailers but did not come up with much. Try Charlie Litchfield @ WIT 800-940-0197, he will be able to set you up.
Glad to hear some of you have dodged this problem, unfortunately millions of others are dealing with T-case failure. I am not sure if it has been discussed here but since the pinhole leaks are so high up, oil only comes out in small amounts when driving and there are rarely any spots in the driveway to act as warning sign. If not caught in time the T-case melts down on the highway. The degree of wear is directly related to the amount of internal movement of the parts leading to fretting wear. I don’t think it has as much to do with the way it is driven, as much as tolerance of the parts when it leaves the factory.
Glad to hear some of you have dodged this problem, unfortunately millions of others are dealing with T-case failure. I am not sure if it has been discussed here but since the pinhole leaks are so high up, oil only comes out in small amounts when driving and there are rarely any spots in the driveway to act as warning sign. If not caught in time the T-case melts down on the highway. The degree of wear is directly related to the amount of internal movement of the parts leading to fretting wear. I don’t think it has as much to do with the way it is driven, as much as tolerance of the parts when it leaves the factory.
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