RPetty

[QUOTE=Lizard931;7800566]

Then cut out the center of the rear cross member between the transmission mounts, and instead have a piece welded onto either side so that you can bolt a bar to replace the piece that was removed.
Then you can pull the transmission/TT without having to touch the rear suspension.

Hey
would you have any pics of this process? Or known links? This is very interesting to me...

mark kibort

Unfortunately Brian, you owe me a beer!

bummer! well, you will be happy if you get a 85 transmission. it makes racing a 928 really fun! if you only need the 5th gear, talk to scot for his donor transmission as he is pulling it to put in an S4 tranie.

Originally Posted by IcemanG17
If you can see metal through the TT holes...then it appears the TT is broken...which is good and bad...the good news is a rebuilt TT is only $400.....so its fairly cheap.....the downside is its a bit of a PITA to do.....

MK
Sounds like you owe me a beer!!

RPetty

[QUOTE=mark kibort;7800795]

"if you only need the 5th gear, talk to scot for his donor transmission as he is pulling it to put in an S4 "

Mark I'll keep it in mind.
I'm looking into the Euro I have access to.

Many thanks

mark kibort

why do you want the euro box? same crummy synchros. Unless its a great price, I would think of rebuilding. then, everything is new inside that matters.

however, between the new or used 5th and the synchros, and other parts it may need, it may just be better to do a new gear box and junk this one.

anyway, good luck.

[QUOTE=RPetty;7800857]

RPetty

[QUOTE=mark kibort;7801932]why do you want the euro box? same crummy synchros. Unless its a great price, I would think of rebuilding. then, everything is new inside that matters.

however, between the new or used 5th and the synchros, and other parts it may need, it may just be better to do a new gear box and junk this one.

anyway, good luck.


Mark,

That's good to know. I'm on a huge and expensive learning curve here. That's why I encourage all the input you guys have.

Keep it up, please

mark kibort

I would say, your best bet is to try and get a S4 or 85-6 box.

The euro has really no value and is probably the same as what you have now, right. same rear end too. 2.75:1 LSD? and by the way, you can still swap out LSDs with the older boxes, but ive heard with the newer ones, that the LSDs wont fit. you need the newer LSDs to work. (But there is a way to make it fit in the newer gear boxes, but its a matter of knowing what to do, shims, etc)

if you can get the new gear and someone takes it apart to see what it needs, it might be better to rebuild yours by someone that knows what they are doing.
the big expense will be the 5th gear, but if that is all that is wrong and you only need to put in 1,2,and maybe 3rd gear synchos, it might be cheap to rebuild and you get something that will be almost new. most of the labor is taking the transmission out and putting it back into the car.

[QUOTE=RPetty;7802367]

Landseer

An 85 or later transmission with the borg warner synchronizers is desireable. Who knows, you might already have one in there?
(If the box is 1980 or earlier, then it might have a different length TT because the very earlier transmissions were slightly different.)
So you need a transmission and matching TT.
You need the right pairing. Either "pair" should fit the car. (Early tube can be notched in a different place to accept pinch bolt for late trans, as SVP said above, but if you are buying , get the right pair.)

Regarding the TT, once you've got the right one, you might consider having it rebuilt using the new Constantine Super Bearings.


I wouldn't consider an earler transmission to have no value. Far from it.
They, too, are strong.
KCCampro just provided me with an excellent 80 Euro box and its going into a lightened 84 car next week, hopefully to see at least a little DE track time!

mark kibort

again, what the heck is a "euro" box anyway? how is it different than the '80 US boxes or even 79 for that matter?

svp928

G28-05 (81-84) Euro box is close-ratio and 2:72 rear gear. The gear ratios are spaced closer together so you don't see as much rpm drop between shifts. Th GT box is very similarly geared. For you, Mark this may not be optimal at Laguna (you would need 4th going up to the corkscrew), but may be good at T-hill. Depends on the track. But, I can tell you, its a BLAST on the street! i have a great deal of fun with my trans and power level, even at Laguna where I stay in 3rd right at 100mph at approaching 8, and leave the braking a little later....I am at the rev limiter going under the bridge up the hill, if I shift, its for less than a second and back to 3rd.
On the street, rowing through 3 gears is just a lot of fun....

Landseer

WSM section 30.

Some reportedly made it into the 80 Euros, along with longer TT. An indication of the -05 version is if the rear cover is mounted with hex bolts.

If studs/nuts holding the rear cover, that is an indication of the earlier boxes G28-03 which use a shorter TT, but shares same gearing.

According to the manual, G28-03, followed by G28-05 beginning June 1980 production, had 2.75:1 until mid Jan 1981 production, then 2.72:1 (a nuance in case somebody is swapping parts to make a box)


I've been experimenting with Jadz928's 84 Euro. Definitely different gearing.

Getting ready to put a similar box in an 84 USA, replacing a G28-08 that needs some TLC.

mark kibort

I didnt know there was a gear box that was close ratio. hmm, Ill have to check out the specs of the "05".

I still use a tad of 4th up to the corkscrew, and turn 5 as well. before the stroker, i could redline to both the corkscrew and turn 5, and near redline to turn 6. (118mph) . Up the main straight ("hill" ?) 3rd gear to the flag tower bridge with the stroker, and just past it without it as you probably saw from the videos. Anyway, so, the 2.2 is highly optimized for laguna. T-hill, the 2.72 might be better, as I have driven the 2.75 '79 there with only 200rwhp and it was ok. Hard to have a knee jerk answer, as it really depends on so many things (track, power, speeds, shift points etc).

I did have a chance to drive scots 2.75 around town for a while and through a few races. it was ok. nothing earth shattering revolving around the gear ratios. Its really about the spacing and am now curious if the euro box really has closer ratios.

thanks

mk

svp928

MArk, by virtue of the different "layshaft" gearing, it makes for closer spacing- my car barely drops 1000 rpm between gears. Its in the WSM transission section, if you care to see what the exact differences are. Combined with the shorter rearend ratio, it makes for fun driving f you shift quickly enough. If you don't, and let the revs drop before you let the clutch out again, you get pretty good forward whiplash and think you left it in the last gear....I can also shift this without the clutch fairly well because the ratios are so close together. Downshifting w/o clutch is still tricky, though.....
Synchro's aside, the older boxes can be great fun. Mine are about 30k old now, but still work fine, so I have some trouble understanding all the angst about pre-85 manuals. BUT, Greg Brown rebuilt this one some 10 years ago, maybe thats why it works!

mark kibort

Steve, I have to jump in and save you from the dangers of "perception"

The 05 (euro 2.72) , the 07 (US 2.72) and the 08 (US 2.2) all have near IDENTICAL gear rations and near identical gear spacing. The ONLY difference is a very slight difference between the 05s shift from 2nd to 3rd, but all other shifts are identical as far as spacing (excluding 5th)
(i.e. for the euro (-05) box:
66% drop for 1st to 2nd
75% drop for 2nd to 3rd,
74% drop for 3rd-4th

The US 2.72 (-07)
66%
71% the only reason it is not as close, is due to the shorter gearing of 1st/2nd
75%. so, actualy closer ratio her than euro

the US 2.26 (-08)
66%
71%
75% also closer ratio here vs euro

More noteworthy are all the 3 above gear boxes have near the same ratios as well.

-05 (2.72 euro)
9.7
6.5
4.9
3.64

-07 (2.72 US)
10.2 (actually shorter than euro)
6.8 slightly shorter to euro.
4.86 near identical to euro
3.67 near identical to euro

-08 (2.26 US)
9.65
6.41
4.58
3.45)

S4 2.2 has a slightly taller 1st, same over all spacing, and a 4.5 3rd, and 3.3 4th, which are very close to US 2.26 by only 4% difference which is much less than when I put 305 tires vs stock diameters, so the difference is VERY slight)

Now, you may have a great rebuild from Mr Brown, but your ability to shift with no clutch is pure skill and has nothing to do with the ratios of a '05 box.

svp928

Mark, did you look at the layshaft ratios? If I get a minute, I will check it. That ratio, I think is the biggest difference. Combined with the short rear gear, it makes the spacing seem very close...

Landseer

Here's the ratios for the early transmissions and the cars that got them.
(I don't understand them very well, but here they are -- maybe you guys can explain)

Note how the 1980 Euro S got the G28-05, while other 1980 928's got the G28-03.
Two different TT's that year. Same gear ratios, though the -03 isn't shown here.

Note also the G28-07 which is in ROW cars for 1983 and 1984. (That might be the one Mark isn't so familiar with)

That -07 is what Jadz928 has in his 84 EuroS that feels so different, maybe its the interesting one.
So the -05 I'm getting ready to install is not the same as the -07.
Just same TT length, since -05, -07, -08 and later all use the same.