g5mr vs g25mr

[Gomez]

I tried searching and can't find any straight up info about what the differences are. FF.com google wikipedia nothing. I did see one post on mazda.com or something like that where someone said he thought they had the same internals. Wiki said the g5mr was an upgrade but they didn't say from what. And Wiki couldn't post results of a g25mr search. I was about to buy a tranny the other day but am glad I waited. Now I have to wait until I get proper info from the Festivians. What's the difference? Which one would I be better off with using a GOOD strong running BPT? Also are all the EGT trannies Hydro?

Is there a good link to the G-series trannies telling what they all came in, which ones were hydraulic, mods, or anything? Thanks guys.

[Zanzer]

Did you see this?

http://www.fordfestiva.com/forums/sh...ad.php?t=11540

[Damkid]

The g5mr is the Capri XR2 tranny (cable) the g25mr is for lack of a better word is the "second generation" (hence the "2") meaning it was found more in the BG chassis cars (EGT, protege, etc) and they are hydraulic clutch... Internally they are identical and the casings are the same strength, the only differences would be slightly different gearing

[Gomez]

Yes I did, but it really doesn't answer any of the above questions. What is the difference between the 2? It shows the XR2 with a g5mr. In other searches I see people saying g25mr. Halfway through the Escort, Tracer, and Protege model years they change from one to the other. It says the 323gt and XR2 use a cable clutch and the rest use a Hydraulic clutch. Then the thread says the XR2 uses a cabled g5mr and a 91-92 EGT uses a hydraulic g5mr therefore I would have to assume that a pretty major change like that does not effect model #.

What kind of horsepower ratings do they have?

That thread just seems to leave so many questions unanswered.

[Damkid]

Before I learned more about the g series tranny's, I'd call all of them g25mr, so who said g5mr's were in the escort gt's may not have realized the difference with the "2" which is a simple enough of a mistake

I'd think once you start getting 300+hp is when you'd be changing tranny's after every trip to the track lol below 300, you should be alright

As far as I know only the 323 gt and Capri xr2's had cable g series tranny's, and as far as i know all escorts, protege's, tracer's etc. with a g series was hydraulic

[FestYboy]

and also something to note, the F series 1.6L proteges and BP proteges run the same manual final drive gearing and the B8 F series is lower... also the B8 F series trans is only 0.031 higher than our 5 speed E series (all info gathered from factory 92 protege and 89 festy manuals).

[Rocketman]

G5MR and G25MR don't refer to the casings at all - it's not an accurate way to differentiate between the transmissions. If you look at this list you will see that the early BG chassis also got a G5M:



For all intents & purposes, the internals are the same minus some gear ratio differences. The final drives may be a bit different between the two, but the major differences are in the clutch actuation & they have different cases.

The 323 GT & Capri XR2 had a cable - actuated G-series as Damkid said. These originally came mated to the B6T engine

The other G-series from the BG chassis were all hydraulic with a slave cylinder. These transmissions came mated to the BP & the bellhousing is clocked differently as compared to the cable type, the BP engine leans forward several degrees in the BG. Typically these transmissions also utilize a motor mount on top of the trans as well

Horsepower ratings are a bit tough, because a lot of it depends on the car behind the trans (weight wise) and the way you treat it. The differentials in any g-series is a weak spot, the spider gears & pinion shaft don't hold up well to one-wheel wonders (I have seen people with stock B6T's repeatedly blow through transmissions because they won't stop the burnouts. On the other hand I've seen people with high HP B6T's & BP's last just fine because they don't abuse it). 3rd gear can start to strip if you're making enough power (300+whp), but I've only seen this happen on heavier cars like the probe & 323 GTX.

Im sure someone can pull up some specific pictures of each type of trans for you. Hope this helps though, yeah it's a bit confusing but will eventually make sense
-Rocket

[Gomez]

Sorry Chris. I was in the middle of posting when you submitted your first post. I don't want you to think I was ignoring what you did post.

Thanks all of you. I think all of my questions just got answered. Being that a 323GT is a rare thing around here it looks like it will be XR2 for me. Thanks again guys,

edit: I will be building the BPT (prolly JDM) a little, I doubt I will be adding that much HP. If it comes out at around 225-250 i'm a happy camper.

[fastivaB6TG25MR]

im on the same page with damkid... my name should be fastivab6tG5MR...there is alot of misinformation. not intentional but this stuff can get confusing. the biggest difference i found is that the g5mr's seem to have the taller 3.85 final drive instead of the 4.10's of the egt and protege... which in my opinion makes it a way better turbo gearbox as well as a better fuel economy option.


edit:
for longevity and power handling i strongly recommend you not have any of the diff gears replaced during a rebuild. i know it sounds stupid but the gears that the stock mazda parts superceed to are very weak. i had one last less than a month of street driving and after it was replaced a second time(for $200 cause the deemed it abuse not part failure) the brand new spiders shattered 2 days later on my first pass at the track. the tranny shop agreed that the gears they were getting from ford were garbage and sourced out a good used stock xr2 diff for free. to give a comparison i used junk yard xr2 tranny for almost a year of street/track 1/4 racing with only synchro issues.they take a massive amount of beating when left stock.

[Gomez]

^great info. Will make a note of it.