gearbox rebuild, need your opinion! please :)

[folkevogn]

Dont you think its exaiting to guess (read: "wonder how ecspensive its going to be this time") what has gone wrong, when you have a tranny breakdown. well....I like to have an opinion witch is based on  what sounds I heard when the breakdown accurd and afterwards. This time my guess was wrong   I thought that one the clips that hold the main shaft and pinion shaft had fallen of,  because it look like the main shaft was wiggling around when took a peek tru the filling hole. But I wasn`t very surprised when I saw my first gear peeled clean For the second time, and this time I only got to do a second gear burnout before I brook my first gear 30cm after I passed the photocell 

After checking the house of the gearbox, I saw that there was som damage around the hole where the main shaft enters the diff-house. The bearings didn`t look damaged. Last time I brook the gearbox I asked gearbox builder if I had to change the housing. He said it wasn`t any problem, so I changed the brooken gears and tried again.(yes..I know I should change to more heavy duty gears  but I am a student at the moment, so that wont happend this year)

whats your opinion?? should i change the housing every time, or can I use it over and over again?? Is it possible to just change the bearing(can it be worn out because of the breakdown and have some unwanted play?)

The gearbox housing is a 1302 with swing axels
3.88 r&p
superdiff
original key`ed first and second
welded third and fourth
heavy duty sideplate

[Alan Uyeno]

If you have some power the stock keyed 1st/2nd mainshaft is a weak point. Substitued the 10 tooth first and get at least a 9 tooth later mainshaft.

[folkevogn]

Hmmm,I haven`t counted the tooths, will do.... I didn`t build the gearbox the first time, but I think the mainshaft was swaped for a later model 9 tooth.(if someone have a used heavy duty aftermarked 1st and 2nd gear for sale, I might digg deep in my student pocket  3rd and 4th is 1,56 and 1,14 )

But my main issue is still what to do with the gear housing.Use it or get another one?? I found a new(used offcourse) yesterday, but it will save my alot of work using the old one.(dont have to set up diff, R&P)

[SOB/RFH]

Here is a fact you might take in consideration. You can swap the late gear box housings (IRS and bit M80*1 nut holding the pinion bearing) whitout changing the shimming fo the R/P as they are very accurate and allways comes witht he same shimming (it differs with the ratios on the R/P) from factory.   

[folkevogn]

"You can swap the late gear box housings (IRS and bit M80*1 nut holding the pinion bearing)"

so your saying I can take a gearbox housing from another car, and if it has a 3.88 R/P i dont have to do anything with the R/P.(that makes it alot easier).Can I also swap 3rd and 4th from my old gearbox directly on the new one, or do I have to make some adjustments?Sorry for the stupid questions, I still have alot to learn.

Correct me if I`m wrong, but by this your saying I should change the gearbox housing for sure??(no one has given me a clear answer yet  )

[Jee Ent.]

If it's not cracked, badly damaged or ruined any bearing surfaces...you don't have to change it.  The magnesium alloy don't take any prisoners (if it's not heated that is). Either it cracks or holds. You could never bend it.

[SOB/RFH]

You acn swap the case but have to set up the third and forth gear correctly if changed.

[folkevogn]

thanks for all the replies. It has helped on my small knowlegde of gearboxes.

After a discution with Erik(Jee Ent.) I have come to the conclution to use my housing and just change the 1st and 2nd gear.Just gone check the housing for cracks and clean and remove loose bits.
Hope it works a little bit longer this time 

[JS]

Yeah, I thought 10ft. was a little on the short side 

[kormi]

the 10 ft club is getting bigger... 

[folkevogn]

I cant deside if this is a cool club to be a member of 

[Jee Ent.]

A great club with a lot of members...

There is only one club that is better, and even harder to get in to.   The "do the burnout in reverse" club ;-)

[Tekken]

A great club with a lot of members...

There is only one club that is better, and even harder to get in to.   The "do the burnout in reverse" club ;-)