weird tranny problem. 1st gear maxing at 20mph

[jeffputts]

hey guys, ive got a weird tranny problem going on. heres the lowdown. 89 GT with a 5 speed Bog warner tranny thats about a year old in it. i changed my spark plugs and wires a couple weeks ago and as soon as I did that my first gear got really weird. It is maxing out at about 20MPH. the RPM's will keep going up, but the car wont go any faster. I realize its not related to changing out the plugs, but it is so bizarre that it would happen at the same time. the rest of the gears are fine, its only first that is doing that. any ideas would be greatly appreciated. thanks

 

[5.0Droptop]

prolly crossed some ignition wires.

 

[jeffputts]

alright I'll check those out again, it's not running rough or anything though

 

[5.0Droptop]

worth checking since it didnt happen untill you changed plugs. What plugs did you put in it and did you gap them properly?

 

[jeffputts]

i put in autolite 25's gapped to .54 the plugs that the previous owner put in were bosch platinums. the car is running extremely lean also

 

[95bluegt]

i had the same problem get the plugs to factory and get a good custom tune for the fule being lean. as for the first gear toping out at twenty the synchro could be shot or the the tranny gearing could be junk. plus if you have a high gear in the rear end the gears will be short.

 

[Carney Woods]

I could also be your clutch is starting to slip........

 

[dragnazz5.0]

I could also be your clutch is starting to slip........

yeah, im g0nna have t0 g0 with that als0. spark plugs and wires will n0t make y0ur rpms g0 up and y0ur speed n0t increase. drive d0wn the r0ad get t0 ab0ut 30 mph, put it in 4th gear and put the pedal t0 the fl00r. y0u will be able t0 tell if its slipping. but im pretty sure thats what y0ur pr0blem is

 

[ls1beater4eva]

i would recomend putting a new clutch in the car b/c spark plugs would havae nothing to do with mph really and syncros dont either unless you just cant get into gear.

 

[tunedin302]

I have a suspicion that it is your clutch. Go out on the highway and put it in 4th gear - get to around 2000 rpm and floor it. Chances are your clutch will slip and if so, that is probably your problem.