Just finished installing everything and finally test drove the 122s with the m46. The problem I'm having is the first gear is really short and when you stick it into 2nd its a huge diffrence in gearing. Its almost better to start in 2nd and never use first. The car used to be an automatic, then I placed a m40 then installed the m46. I think the whole problem is the rear axle. Can anyone help me with this? The other problem is almost a hard kick every time you place it in 2nd. Almost feels like the tranny wants to come out.

Sometime after 1980 the M46 got a shorter first gear.
That's when they went to the 3.73 rear end on most cars instead of the 3.91.
I had a 1980DL that I swapped in a M46 for a M45 and noticed quite a bit of difference in the first gear. So I guess an earlier M46 would be more desirable except for being used longer and having more wear. I wonder if you could swap out the first gear$$$$.

One of the least desirable traits of the M46 is the short 1st gear. That coupled with short rear axle and you've got exactly what you describe; a useless 1st gear.

Not sure what help you're looking for but what you describe is what I'd expect.

The lurching going into 2nd might be solved by shifting a little more slowly and letting the engine slow down a bit before letting out the clutch...
--
Dale

Is is possiable to change the gear ratios on the rear diff to better match the m46 tranny on a 122s?

It is possible but difficult and expensive.
I'm not sure why you changed to the M46, but you do your differential to match 4th gear, NOT first.
Unless the M46 has overdrive the final ratio will be the same and the difference between 1st and 2nd
will still be there no matter what differential ratio you have.
--
George Downs, Bartlesville, Heart of the USA!

The M46 was installed in a car that weighs a good 500lbs more than the 122 and around 300 more than a 140--so they lowered (by a lot) 1st gear to get the 240 moving and made the diff ratio longer for lower revs on the highway--a little bit on early 240's (3.91) and later a lot (3.31) for mpg's. One thing I've always loved about the M40/41 is the relatively long first gear -- not so great for doing burnouts but much more comfortable for driving in traffic. Seems like a good time to consider converting to a disc brake rear from an 1800E so that you can then fit the more moderate gears from a 240 or 260 --the choices would range from the 3.31 to 3.54 to 3.70 to 3.90 -- The much longer ratios than the 4.10 you now have will make the car less lively in the upper gears but give you more flexibility in the lower gears -- the 3.7 would make a very noticeable difference but should allow you to drive the top gear without too much shifting in and out of OD on the hills. Redoing a rear with used parts is very doable if you have the know how. You can't really do anything about the long jump from 1st to 2nd. The other tact would be to just forget about 1st except for starts on a grade--use 2nd-OD--sort of like the 4-speed truck transmissions with the stump puller 1st. -- Dave

I wish I had a rear end of a p1800 with disc. I actually have a good story about that. I found a p1800 in a junkyard one completely rusted but had ipd headers, fuel injection, rear end with disc that bolts directly to the 122s. I was going to strip the entire car but the next day when I went back with tools they crushed the car. I was pissed. Currently my 122s has a engine from a p1800, cooling system from a 140, and trans from a 740. Got to love volvo. Next I will install a AWD unit from a xc70 :) J/K