BCB vs BRB

**Mooserini** · 10-28-2010

2000 GP GT 4d 182k - Perfect engine, body, chassis etc.

What exactly is the difference between the BCB transmission submodel and the BRB? I am looking at replacing my transaxle due to first gear takeoff issues (wish it was a simple fix, otherwise the trans is PERFECT) anyhow... I am finding them all over but I have NO id tag on my trans now to tell if I am running a BCB or a BRB and I have no idea where to go from here. Anyone have any luck with the solenoid changes?

Problems are:

Once warm it slips from a stop (shuddering as if though grabbing and releasing the clutches), however once you're in second it's fine and if you stab the gas it'll downshift into first and not slip a bit. This is resolved with no shudder or slam by manually selecting first gear then going to drive after it winds out)

Sometimes when merging into traffic and easing on the gas the tach will bounce like the Torque converter is locking and unlocking - this is resolved by applying more pedal to unlock the converter OR letting up so it isn't in that almost ready to unlock stage. Otherwise shifts are GREAT.

**Lawngoose** · 10-28-2010

Originally Posted by Mooserini

What exactly is the difference between the BCB transmission submodel and the BRB? I am looking at replacing my transaxle due to first gear takeoff issues (wish it was a simple fix, otherwise the trans is PERFECT) anyhow... I am finding them all over but I have NO id tag on my trans now to tell if I am running a BCB or a BRB and I have no idea where to go from here. Anyone have any luck with the solenoid changes?

Problems are:

Once warm it slips from a stop (shuddering as if though grabbing and releasing the clutches), however once you're in second it's fine and if you stab the gas it'll downshift into first and not slip a bit.

Sometimes when merging into traffic and easing on the gas the tach will bounce like the Torque converter is locking and unlocking - this is resolved by applying more pedal to unlock the converter OR letting up so it isn't in that almost ready to unlock stage. Otherwise shifts are GREAT.

4T65eHD infomation

**Mooserini** · 10-28-2010

Originally Posted by Lawngoose

4T65eHD infomation

Don't see a BRB in there anywhere :/

**Bio248** · 10-28-2010

i have no idea what youre talking about with BCB or BRB...

your transmission name is the 4t65-e.

**Mooserini** · 10-28-2010

Originally Posted by Bio248

i have no idea what youre talking about with BCB or BRB...

your transmission name is the 4t65-e.

there are different configurations of the 4t65(hd) transaxles and I want to find one that will work without PCM changes and I'd also like input on the possibility of just fixing mine. I have the option according to car-part.com interchange of the BRB or BCB trans.

**Mooserini** · 10-28-2010

I will be patient here, I am no expert but I already have found out the information I need to get this car to A+ shape. I cannot justify junking it as it looks perfect, runs perfect and the interior looks showroom. I just want my tranny to stop acting like paris hilton.

**Bio248** · 10-28-2010

there are two configurations, the 4t65-e and the 4t65-e-hd. you have a GT so you dont have the HD transmission. so long as you pull it from another grand prix GT or SE (NOT A 97) then its plug and play.

**Mooserini** · 10-28-2010

Originally Posted by Bio248

there are two configurations, the 4t65-e and the 4t65-e-hd. you have a GT so you dont have the HD transmission. so long as you pull it from another grand prix GT or SE (NOT A 97) then its plug and play.

I realize I don't have the HD as I don't have a supercharger. So either the BCB or the BRB would work (same final ratio etc) since they were both used in the non supercharged 3800 grand prix that year?

**noreasonwhyy** · 10-28-2010

you'll be fine with any trans from a n/a w-body 98-02.

can you link me to something that states what the bcb and brb are and differences between them? never heard of them

**Mooserini** · 10-28-2010

Originally Posted by noreasonwhyy

you'll be fine with any trans from a n/a w-body 98-02.

can you link me to something that states what the bcb and brb are and differences between them? never heard of them

I wish I knew, that's what I am looking for. The link that was posed above shows the BCB in the different tables, but no sign of BRB. When I search car-part.com for local salvage yards it asks me which one. When I choose BRB it seems like there are a wider variety of vehicles using that, but the BCB seems to be 2000 model year specific with various vans and even the 3.4 using it... which according to that table doesn't make sense.

**16MustangVet** · 10-28-2010

Do you guys know how many different GM FWD configurations their are for gear ratios vavle bodies, TQ convertors ect?? Hes on the right track by looking for the same code on the transmission ID tag. Id reccomend emailing Triple Edge Performance they know everything! Yes you COULD find another trans from the same type of car but it will have a major impact on the ease of finding a matching one if you know what the trans ID tag is compatible with.

**DaytonaGTP** · 10-28-2010

^^^x2... triple edge will know. if not then we'll all die...lol

**torq455** · 10-28-2010

I googled 4T65E brb and got a lot of Chevy Venture info. Then the bcb gives me Venture, Silhouette and Montana info. Those iirc. have a FDR of 3.69.

**Mooserini** · 10-29-2010

Originally Posted by torq455

I googled 4T65E brb and got a lot of Chevy Venture info. Then the bcb gives me Venture, Silhouette and Montana info. Those iirc. have a FDR of 3.69.

I am somewhat of a tard when it comes to tranny's... so what is iirc? Ty in advance.

**Bio248** · 10-29-2010

IIRC = if i remember correctly

**matt5112** · 10-29-2010

Well....

GM 4T60-E transmission - Wikipedia, the free encyclopedia

M15 — 245 mm (9.6 in) torque converter
MN3 — 258 mm (10.2 in) torque converter
MN7 — 258 mm (10.2 in) torque converter and heavy-duty gearbox (see 4T65E-HD)
MD7 — 245 mm (9.6 in) torque converter (Chinese version)
M76 — 245 mm (9.6 in) torque converter (with all-wheel drive capability)

You should find codes like that.

**Mooserini** · 10-29-2010

Originally Posted by matt5112

Well....

GM 4T60-E transmission - Wikipedia, the free encyclopedia

M15 — 245 mm (9.6 in) torque converter
MN3 — 258 mm (10.2 in) torque converter
MN7 — 258 mm (10.2 in) torque converter and heavy-duty gearbox (see 4T65E-HD)
MD7 — 245 mm (9.6 in) torque converter (Chinese version)
M76 — 245 mm (9.6 in) torque converter (with all-wheel drive capability)

You should find codes like that.

That still doesn't tell you the final drive ratio and what not. I am going to call that trannyguy and see what he has to say. Thanks for your help though!

**matt5112** · 10-29-2010

If you check application it does tell you based on the one of those codes.

**Mooserini** · 10-29-2010

Originally Posted by matt5112

If you check application it does tell you based on the one of those codes.

I totally agree, but there's a subcode also. bcb and brb... apparently two different final drive ratios. I suppose I'll have to do this the old fashioned way and make it rear wheel drive with a turbo 350 tranny and a 350 v8 lol

**noreasonwhyy** · 10-29-2010

The Grand Prix GT and SE with the L36 engines have a weaker transmission than the GTP with the L67 3800 SC, but it's not a 4T60e, except in some 1997 GTs, which is really an oddball year. All '98 and newer L36 engines have a 4T65e, but they have the light duty version, RPO code M15. All L67 engines have the 4T65e HD, meaning heavy duty (RPO code MN7). The differences? The MN7 version have a larger differential, and due to the larger differential, the output shaft on a MN7 is about 1/4 inch longer. The MN7 also have a stronger input sun gear, and have roller bearings on the differential housing whereas the light duty 4T65e have a bushing instead. There may be some other minor differences inside, but these are the major ones. Can you convert a light duty trans to a MN7? Yes, but those pieces are a bit pricey.

By the way, the 4T60e (RPO code M13) is a much lighter duty transmission than any 4T65e.(that's in most '97 GTs).

...

All 4T65e transaxles actually have the same 3.29:1 ratio differential. Yes, we know that the GT has a final drive of 3.29:1 and the GTP has a 2.93:1 final drive (in fact, all L67 3800 SC engines, and hence MN7 transmissions, have this 2.93:1 final drive.

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