NA 525 Vs. Turbo 525

[plymouth]

Is the 525 in a NA car the same 525 in a turbo car? I have an 87 omni that I am swapping to turbo and I would like to know if they are the same. I know the 525 is really weak but I don’t think I would want the weaker version of the weak trans that just sounds unpleasant thanks.

[cordes]

Unless I'm mistaken the only difference between the NA 525 and turbo 525 in the GLH cars was the FD. I believe that to be the only difference between the other versions too.

[sdac guy]

Unless I'm mistaken the only difference between the NA 525 and turbo 525 in the GLH cars was the FD. I believe that to be the only difference between the other versions too.

Nope. The turbo A525 had a heavier duty gearset. I had to buy a new one for my Omni years ago. And had to find the heavy duty one at a dealer. Actually, I bought it from LRE and Bill Lambros was the one who found it.

Barry

[plymouth]

Thanks, do you have any idea how the NA will hold up to a stock mitsu TI?

[cordes]

Nope. The turbo A525 had a heavier duty gearset. I had to buy a new one for my Omni years ago. And had to find the heavy duty one at a dealer. Actually, I bought it from LRE and Bill Lambros was the one who found it.

Barry

That is very interesting. Do you have any pics of the heavy duty gear set? I have a set out of a 3.05FD trans in my basement. Perhaps we could do a comparison and put it in the KC?

[bakes]

This is why i think the 525 get a bad rap , although it is week compared to later brother's, a alot of N/a gear boxes get swapped into a turbo car only to go pop to soon.

[Marcus86GLHS]

".....The turbo A525 had a heavier duty gearset. ........"


i never knew that.

[plymouth]

".....The turbo A525 had a heavier duty gearset. ........"


i never knew that.

It looks like not many did.

[Keito]

If I'm not mistaken, isn't there a "Z" welded on the bottom of the turbo 525 trans's? I was told that years ago and all the GLHT's I've seen have a Z on the bottom.

[cordes]

If I'm not mistaken, isn't there a "Z" welded on the bottom of the turbo 525 trans's? I was told that years ago and all the GLHT's I've seen have a Z on the bottom.

I'll have to check my trans cases. I think I've seen that before on a 555?

[sdac guy]

That is very interesting. Do you have any pics of the heavy duty gear set? I have a set out of a 3.05FD trans in my basement. Perhaps we could do a comparison and put it in the KC?

Some time after I posted that last I was thinking and realized my use of the term heavy duty was wrong. The correct term (at the time and in the FSM) is a "hardened gearset". From that, I would gather there probably is not much difference in appearance, only strength.

Barry

[sdac guy]

This is why i think the 525 get a bad rap , although it is week compared to later brother's, a alot of N/a gear boxes get swapped into a turbo car only to go pop to soon.

I don't think that was the reason at all.

Back in 1993 I recall Ed Peters at SDAC-3 tech session stating the turbo A525 was good for about 250 lb/ft of torque. Over that and it became questionable, depending on how it was driven. Ed was a former Chrysler engineer that earned his living doing part failure analysis.

Barry

[OmniLuvr]

^that sounds about right, every time i turned the boost up to 18 psi, my tranny wouldnt last to much longer after that...

[plymouth]

Cool thanks for the info I will keep the boost low.

[BadAssPerformance]

Some time after I posted that last I was thinking and realized my use of the term heavy duty was wrong. The correct term (at the time and in the FSM) is a "hardened gearset". From that, I would gather there probably is not much difference in appearance, only strength.

Barry

This sounds right. MP offered a "hardened diff gear" set for the A525.

+1 on the different ratios. 3.87:1 or 3.56:1 or the elusive 3.50:1 in older carb cars

Also, the A525 can be stengthened by the MP or LRE girdle to support the case from flexing the diff right out of it...

[rbryant]

525s are worse than any other transmission option that you can put in our cars turbo transmission or not.

If you have one out and it isn't a numbered car that you don't want to cut a single hole in then it would be better to just get a 523. I personally wouldn't put a 525 back in a car that I own for any reason.

-Rich

[4 l-bodies]

There were constant ongoing changes made to the 525 through at least 87. For the most part, the turbo, HO, and then the minivans received the good parts. As stated earlier the FD ratio was unique to the turbos. Like Barry said, speed gears were hardened. HO applications also received these. High strength diff. side and pinion gears once again for the HO and turbo applications. Slight changes to the case took place throughout the years, 85 had dual shift fork, 87 had intermediate shaft mods at 2-3 thrust washer. 85 had 8 hole diff bearing retainer cup, earlier versions had 5 hole. 87 had changes to sychronizer stop rings. Shift fork changes for 86 & 87 as well.
You learn this stuff when you hurt them... I need to purge this useless info and make room in my brain for something more important.
Do yourself a favor and install a 523 and don't worry about it. Should I ever pop another 525 in my GLHT (#5 in 45K) no way will another one be going back in. I now know when to say uncle.
Todd

[rbryant]

There were constant ongoing changes made to the 525 through at least 87. For the most part, the turbo, HO, and then the minivans received the good parts. As stated earlier the FD ratio was unique to the turbos. Like Barry said, speed gears were hardened. HO applications also received these. High strength diff. side and pinion gears once again for the HO and turbo applications. Slight changes to the case took place throughout the years, 85 had dual shift fork, 87 had intermediate shaft mods at 2-3 thrust washer. 85 had 8 hole diff bearing retainer cup, earlier versions had 5 hole. 87 had changes to sychronizer stop rings. Shift fork changes for 86 & 87 as well.
You learn this stuff when you hurt them... I need to purge this useless info and make room in my brain for something more important.
Do yourself a favor and install a 523 and don't worry about it. Should I ever pop another 525 in my GLHT (#5 in 45K) no way will another one be going back in. I now know when to say uncle.
Todd

Very well put and very good information.

I agree completely. There is no reason to take a 525 out if it is working but putting one back in just isn't worth the effort. In order to find one that will hold up you will spend more time and money than it would take to put a superior quality 523 in the car.

I also suggest getting a 523/568, and cables ahead of time and stashing them in a corner somewhere so they are ready if needed.

The best time to upgrade to the 523 is when you wear out a clutch because depending on the year the 523 might have a different input spline than your 525. It is also a time when the 525 has to come out of the car anyway.

-Rich

[plymouth]

If you guys want to donate a 523 to the omni I will gladly let you. I am not building a race car just a daily car to get my butt to and from work because my sundance is not a good DD.

Now I heard that in 87 and up the 525 got a redesign and that was suppose to fix some of the blowing up that the 525 did. Does this redesign change enough for it to hold up?

[4 l-bodies]

If you guys want to donate a 523 to the omni I will gladly let you. I am not building a race car just a daily car to get my butt to and from work because my sundance is not a good DD.

Now I heard that in 87 and up the 525 got a redesign and that was suppose to fix some of the blowing up that the 525 did. Does this redesign change enough for it to hold up?

Donate?... Locate a tranny and go to the salvage yard and pull the tranny like the rest of us. I bought my last 92 523 for $85. It had under 90K on it.
Yeah the 525 will hold up just fine for their intended purpose if you drive it nicely and it has relatively low mileage. After turbocharging, yours doesn't fit that category does it? Chrysler gave up on the whole design after 87 (except for the TBI L-bodies). That should be a REALLY BIG hint to you.
So if you don't care about performance just reliability, why are you making the big effort to change a N/A Omni to a turbo? If you only want something that will get you only from point A to point B reliably, I have to ask, why are you choosing a entry level car that's 23 years old?
Todd