What makes a BRF a BRF?

[54Rich]

The continuing saga of buying something that not quite what the seller said it was. If you read anything I've typed lately, you'll know that the engine was junk! Now the trans that was supposed to be out of a GN, isn't. No tag, a engraved number of 4HP455254 and a AK valve body, I didn't check the governor. I can't find anything on these numbers. So if I was to find the parts, what makes a BRF a BRF? Valve Body, Gov, and, ?? (so now I need a transmission or can I use what I have and it gets modified?) Thanks, Rich

 

[GNVAIR]

The general consensus has been the BR coded valve body which has 2 pressure switches
The governor
The servo assembly
and if you want to get technical the BRF tag in turquoise (86) or yellow tag (87)
There will also be a partial VIN# just above the left side pan rail that should include the VIN code 7 in the 8th digit indicating a turbo car.
The case details are superficial as all of the later cases are the same castings. Most of the internals are the same as well except for the items mentioned.

 

[Pronto]

You can send it here:

Extreme Automatics.com

Extreme Automatics high performance and drag racing transmissions.

extremeautomatics.com

 

[GNVAIR]

For optics and part numbers
Governor which should have an orange gear for the 3.42s

 

[grass doctor]

ID Year(s)** Application ...letters on tags
KZF ** Olds 442/Hurst
CZF ** Monte SS
BRF ** GN/T-Type/Turbo Regals
OZ ** Hurst Olds
OM Olds 350 Diesels
OG Olds 307
BY V-6 252 Cars
AA and AP Cadillac's

colors for GN tags...but not always true...LOL
blue /turquoise(84/85)
pink (86)
yellow (87)

a brf will usually have pink paint on the valve body...stamped BR on it...
The BRF is a performancel valve body. They also had a larger reverse boost valve and 2nd to 3rd intermediate servo and a specially designed governor assembly. Buick units are identified by the BQ or BRF transmission codes. Monte Carlos used the CZF code. The Hurst Olds/4-4-2 units had a KZF or an OZ code. The governor on a standard TH200-4R valve body is designed to shift at about 3,000 rpm leading to a quick upshift through all four gears using a minimum amount of power. The specially designed governors used in the BRF performance transmissions are designed to shift at over 4,500 rpm making more efficient use of your engine's power band.

 

[GNVAIR]

Servo piston and spring

 

[grass doctor]

ni

For optics and part numbers
Governor which should have an orange gear for the 3.42s

nice!! you got some gold right there buddy

 

[conn84gn]

BQ 1984-1985 Grand National, T-type

 

[turbodave231]

Your trans is a 1987 unit.
The number 4HP455254 is a partial VIN .

• 4 = Buick
• H = 1987
• P= Pontiac Assembly Plant
• The last 6 digits are the last 6 of the original car's VIN

The parts that makes BR, BQ, and CK transmissions unique to other version of the 200-4R are:
Governor
Valve Body

There are other less significant smaller parts like the 1-2 Servo and pressure regulator spring in the pump that are also unique. Normal upgrades make those smaller parts unnecessary. A billet servo is almost always necessary to get a firm 1-2 shift at high power levels.

None of the other versions of the 200-4R are suitable for a performance application. If you try to "modify" the low performance parts to use in a performance application, you will fight the shift quality/timing endlessly.

PM me if you are looking for a valve body.

 

[54Rich]

Your trans is a 1987 unit.
The number 4HP455254 is a partial VIN .

• 4 = Buick
• H = 1987
• P= Pontiac Assembly Plant
• The last 6 digits are the last 6 of the original car's VIN

The parts that makes BR, BQ, and CK transmissions unique to other version of the 200-4R are:
Governor
Valve Body

There are other less significant smaller parts like the 1-2 Servo and pressure regulator spring in the pump that are also unique. Normal upgrades make those smaller parts unnecessary. A billet servo is almost always necessary to get a firm 1-2 shift at high power levels.

None of the other versions of the 200-4R are suitable for a performance application. If you try to "modify" the low performance parts to use in a performance application, you will fight the shift quality/timing endlessly.

PM me if you are looking for a valve body.

Thanks everyone for clearing this up. Reading multiple web pages, I never found any information on my VB? The various websites all claim they can build a Perforamce trans and seem to group all 200r4’s together. I did find a BRF trans that I’m working on getting. Thanks again, Rich

 

[Pronto]

I'ld talk to Lonnie. You can use your case and he has his own vb's that are copies of the BR. Worst case is you buy the whole thing with no exchange. Don't forget you will need a good converter too!

 

[GNVAIR]

General consensus has always been the valve body and governor are matched together and are the most important pieces. The core used doesn't matter as almost everything is the same and the parts that aren't get upgraded/replaced

 

[CKirk]

 

[TexasT]

General consensus has always been the valve body and governor are matched together and are the most important pieces. The core used doesn't matter as almost everything is the same and the parts that aren't get upgraded/replaced

The early units had some different pump castings, and one of the planetaries has a bushing Instead of a roller bearing but that can be replaced if your builder knows and takes the time to do it. The VB/governor is the main thing but there are other VB that have been successfully modified it just takes time and many would rather spend the money and get there quicker.

I am using an AA Cadillac core and it does pretty well, shifts well with some mods and has a larger boost, rev boost and spring to raise internal pressures . I also like the sonnax servo. It is expensive but as above worth the money to me. I didn't want to have a down shift clunk.

 

[GNVAIR]

The early units had some different pump castings, and one of the planetaries has a bushing Instead of a roller bearing but that can be replaced if your builder knows and takes the time to do it. The VB/governor is the main thing but there are other VB that have been successfully modified it just takes time and many would rather spend the money and get there quicker.

I am using an AA Cadillac core and it does pretty well, shifts well with some mods and has a larger boost, rev boost and spring to raise internal pressures . I also like the sonnax servo. It is expensive but as above worth the money to me. I didn't want to have a down shift clunk.

And I said

The core used doesn't matter as almost everything is the same and the parts that aren't get upgraded/replaced

So I was correct.

 

[TexasT]

And I said
So I was correct.

Also important to know who you have assembling your trans. It isn't a "race trans" that the local "race trans" builder will have no problem with. If he doesn't have a satisfied customer list I wouldn't let him work on yours or mine for that matter.

 

[TexasT]

Just saying that a lot of em "know how to do it" and don't want you trying to tell them how to do their job.