If I run a gm lifepo4 and an sla in series to run 36v. Is that bad?

[Sangesf]

And if I then charge it with a 36v SLA charger can that hurt it?

Basically, I'm doing that now and the lifepo is always charged up first and then I use a 12v SLA charger. 

Any thoughts?

[PEDAL IN POWER OUT]

No, it is good.
I don't know which Golden Motor pack you are running. GM tends to have proper battery management and protection built in. I am not surprised your charging scheme gets the job done.
The only minor issue I can think of with that combo, is that the current thru the smallest amperage battery will limit the current for the string, but who cares?  You are not wasting one watt the way you are doing it, unless you have bad taste in wire. It is an inexpensive way to build up the power you need, for the clever individual who figures out how to charge the system!
I know you wont stop there. For your next series battery, have a momentary contact switch on the 'bars to put another pack in series, and call it "TURBO". 
The GM controllers handle massive switch induced transients on the Batt. + input, right?

[TRK]

Mixing different battery chemistry/capacity is just asking for trouble.

[Sangesf]

They are the same capacity. 30ah.

Also.  Does anyone know anybody or place that will help me take 2 lifepo4 batteries with some dead cells and reconfigure them into one 36v for me?

I have one 21v one with a few bad cells (21v 20 ah) and a 24v 30ah one with a few bad cells and need them reconfigured into a 36v xxah and add a 36v BMS.

[e-lmer]

It is a bad idea to run different chemistry batteries
in series.

The battery packs have different discharge curves,
so the SLA battery is going to drop off voltage
at a linear rate while the  LiFePO4 is going to drop
off on a (loosely) parabolic rate.

It means that you may run one or the other in reverse
when it drops too low. That is bad.

Charging this way is even worse.

[Sangesf]

It is a bad idea to run different chemistry batteries
in series.

The battery packs have different discharge curves,
so the SLA battery is going to drop off voltage
at a linear rate while the  LiFePO4 is going to drop
off on a (loosely) parabolic rate.

It means that you may run one or the other in reverse
when it drops too low. That is bad.

Charging this way is even worse.

which brings me to my question about a company that will Fix my older lifepo4s into one.

[e-lmer]

Now we get into a tricky area.

Lithium chemistry batteries are charged by forcing a
high enough current into the cells and noting
how the battery Voltage tracks (because of internal
resistance of the battery material.)

To measure this effectively you want to have identical
cell capacity.  Even then you want to have a balancing
circuit that tries to keep the cells at the same Voltage.

If the cells do not have the same capacity (in Amp-Hours)
it can be unsafe trying to charge them in series.

Also, if you have different capacity cells in the pack,
the smaller cells will be exhausted while the larger cells
continue to hold the Voltage up above the cutoff voltage,
which may damage the smaller cells by over-draining them.

I do not know of any companies that will help you to
build a pack out of cells they don't supply for these reasons.

If your cells are the same capacity you can safely hook the
packs in series to charge, but it would be better to keep the
packs separate so you can charge them independantly
(tho at the same time.)

[Sangesf]

Now we get into a tricky area.

Lithium chemistry batteries are charged by forcing a
high enough current into the cells and noting
how the battery Voltage tracks (because of internal
resistance of the battery material.)

To measure this effectively you want to have identical
cell capacity.  Even then you want to have a balancing
circuit that tries to keep the cells at the same Voltage.

If the cells do not have the same capacity (in Amp-Hours)
it can be unsafe trying to charge them in series.

Also, if you have different capacity cells in the pack,
the smaller cells will be exhausted while the larger cells
continue to hold the Voltage up above the cutoff voltage,
which may damage the smaller cells by over-draining them.

I do not know of any companies that will help you to
build a pack out of cells they don't supply for these reasons.

If your cells are the same capacity you can safely hook the
packs in series to charge, but it would be better to keep the
packs separate so you can charge them independantly
(tho at the same time.)

They are the same cells.

They are both from the same company 
I have pulled out the bad cells, and tested each one that was good after charging them and then putting a load on each one for 30 mins, and they ALL have the same voltage +/- .02 so they are all good, I just have no clue how to put them together, I'm not going to solder them, of course, because that would be bad.

Does anyone know how to connect these cells together without solder?

If I can do that, then I'll do it myself and then just buy a BMS and add it to the new pack.

[MasterCATZ]

whats so hard about soldering ? you obversly de soldered them
o yeh and some large heat shrink tube or plasic to re seal them

not that I can talk I never soldered my pack due to toggle switches I installed to change the configs modes
ie 96V,48v,48v with x2 isolated packs 28v,24v with x2 isolated packs kinda forgotten 30v ~ 70v combos

my cells are sqeezed together behind finger plates .. kinda just like your remote controll batteries are held in
was the only way I could think of to allow for more power later on with out upgrading all the wires and resoldering